Saint Ishiyama Academy Arc

The third story arc in the series, the Saint Ishiyama Academy arc is comprised of Chapters 48-76 in the Manga and Episodes 25-36 in the Anime. This arc details on how the delinquents of Ishiyama High are being transferred to their sister school, Saint Ishiyama Academy, as well as the introduction of the Rokkisei. This arc is also the first to give major glimpses of Oga 's and Furuichi's past, mainly from when they were in middle school.

Synopsis
Spoiler warning: Plot and/or ending details follow.

Class Arrangement
On September 1, at the start of the new semester, Oga is told by Furuichi that they'll be transferring to Saint Ishiyama Academy while Ishiyama High is currently being reconstructed. They head to the school and enter their classrom, where it's revealed that the other delinquents such as the MK5, Red Tail, and Tōhōshinki are also in the same class, despite their age groups ranging. The students discuss this issue with one another until their teacher, Takumi Sadohara, arrives. Sadohara starts off by degrading the class, telling them that their delinquent attitudes and their meaningless violence are disgraceful to society. He then tries to make some examples out of the class by starting with Himekawa, but the third-year replies by unraveling personal information about Sadohara that he gained from his cell phone. Sadohara is clearly scared about it and decides to gain the class's respect by resorting to their idealistic views, mainly with violence. He challenges Tōjō to an arm wrestling match but easily loses. Finally, he decides to go after Oga and take the delinquent to the principal's office for sleeping. He also accidentally wakes up Beel and is electrocuted instead. A substitute filled his place for the rest of the day.

Introducing the Rokkisei
One day, a St. Ishiyama student named Kazuya Yamamura is walking to the classroom for the Ishiyama delinquents and notices the Red Tail members standing altogether. Kazuya starts spying on them until Azusa Fujisaki, a childhood friend of Kazuya's, suddenly appears. Startled, Kazuya then leaves with Azusa and tries explaining why he's so interested in delinquents but Azusa already knows. She figured it out throughout the summer when Kazuya dyed his hair and pierced his ears. As they walk, they notice Hajime Kanzaki along with Takeshi Shiroyama and Shintarō Natsume. Azusa notes how scary Kanzaki is and asks why Kazuya even wants to be like him, though Kazuya states that it's Oga that he's after. The two then follow Oga and Furuichi as the two are walking home, only to see them get surrounded by Teimō Tech delinquents. Oga starts beating up the delinquents but they then find Kazuya and Azusa, taking the latter two as hostages. Suddenly, Aoi appears and helps defeat the rest of the delinquents, wanting to help Kazuya and Azusa. Just as she is about to leave, Kazuya then asks Oga if he can be the delinquent's disciple. Oga is confused by this offer.

At the end of the day, Kazuya visits Oga at his house so that they can go to school together. Kazuya is surprised by the normality of Oga's house but after knocking on the door, to which Hilda opens while feeding Beel, he becomes shocked. Kazuya quickly introduces himself to Hilda and Oga leaves for school, though he tries ignoring Kazuya. Kazuya persists, however, and Oga becomes even more annoyed when Kazuya starts calling him "bro". Oga tells Kazuya that he isn't his "bro" and that he should leave him alone, but after Kazuya continuously praises and shows his respect for him, Oga decides to keep him as his disciple. At the train station, Furuichi calls Oga an idiot for doing so but after Kazuya starts praising him as well, Furuichi calls Kazuya a great guy to Oga. On the train, Furuichi then asks why Kazuya even wants to be a delinquent, especially like the ones at Ishiyama. Kazuya states that while there are students at Saint Ishiyama who are really strong and cool, the delinquents at Ishiyama are much cooler. Oga then asks about the stronger students of St. Ishiyama and Kazuya tells him that they are known as the Rokkisei, or Six Horsemen, a group of students who are involved in many sports clubs and are regarded as the most powerful people in the school. Kazuya adds further that the Rokkisei supervise the school. Hearing this, Oga becomes interested in them and, remembering his goal to hand Beel to someone stronger than him, decides to target the Rokkisei as they're supposed to be strong both physically and mentally.

Meanwhile, two of the Rokkisei members are shown having defeated several other delinquents from Ishiyama. One talks about how disappointed he was in them while another just looks off in the distance, talking to himself that it's been a while since he's seen Oga.

Later, while in their classroom Furuichi notes how there is a large absence of people including the MK5 and Tōjō. Shōji Aizawa states that Tōjō is out working his part-time jobs but that he doesn't know what happened to the MK5, though he did add that he's been hearing a lot of rumors. Nene says that she has also been hearing rumors, saying that it's the Rokkisei. Hajime comments that it's ruining their reputation. The two then start to argue and are even about to fight, but then Aoi enters the room and asks Oga to come with her. They are briefly interrupted by the other delinquents who make comments about Aoi's words, but Aoi ignores them and takes Oga to see Kido, a teacher who talks about student life. Kido tells the two students that they have an authority ranking over the other delinquents (somewhat) before making them class representatives. After which, the two walk back to their classroom but Oga decides to go another way.

In Azusa's classroom, two female classmates start making negative comments on the Ishiyama delinquents but Azusa disagrees, shocking the other two. When Azusa starts talking about the incident with Teimō Tech, she is warned to look out for herself and also after Oga. Much to their surprise, Oga and Aoi suddenly appear outside the girls' homeroom. Oga asks about Kazuya but Azusa tells him that he's not here. Oga is then pulled away by Aoi but he starts talking about the Rokkisei, causing the St. Ishiyama students to start whispering to one another. Oga and Aoi are then confronted by Ichirō Shinjō and Mitsuteru Sakaki while Furuichi is approached by Miki. Furuichi initially didn't recognize Miki, but when he does, becomes cheerful and exclaims how the two haven't seen each other since middle school.

The two then talk about Ishiyama's destruction and also about Oga, and before he leaves, Miki mentions that Furuichi shouldn't try and fight the Rokkisei. Furuichi then asks how to identify the Rokkisei, to which Miki states that they have an emblem on their uniform collar and shows one to him. Furuichi then realizes that Miki is a member of the Rokkisei. In the meantime, Ichirō introduces himself (while adding his nickname) while Sakaki remains silent. Aoi quickly identifies them and accuses Ichirō and the other Rokkisei for wanting to attack anyone who gets in their way. She is corrected by Ichirō who says that they're not using violence, but actually punishment. Aoi is then attacked by Sakaki who uses a bamboo sword against her. Aoi then asks for a ruler from Azusa and uses it in the same manner as her wooden sword, managing to cut off half of Sakaki's sword. Ichirō admits that they underestimated the two and Oga, now excited, gets ready to fight. Oga starts off the match with a trivia questions but Ichirō ignores him and punches Oga in the face. Kazuya then appears and scolds Oga for picking a fight with Ichirō, stating that the Rokkisei has won all of his boxing matches with a single knockout blow and is ranked 2nd best in all of Japan. Suddenly, Oga gets up and berates Ichirō for refusing to answer his question. He asks again but is interrupted with another punch, to which Oga then hands Beel to Aoi so that he can start dodging; it turns out that Oga couldn't dodge the first and second punches because he wanted Beel to know the answer to the questions he was asking. Ichirō tries to land more punches and kicks at Oga but they're all dodged. Oga asks another question and Ichirō answers it correctly, but then Ichirō loses interest in the fight and leaves with Sakaki.

Aoi and Oga return to their classroom, where they learn about an incident that happened to Shiroyama. While trying to defend Yuka and Ryōko from some St. Ishiyama males earlier, his head got smashed with several dumbbells and got sent to the hospital. After hearing this, Kanzaki became enraged and left to attack the ones who beat Shiroyama. Kanzaki eventually finds the students who did it and tries to beat them up, completely ignoring warnings of expulsion. However, he is confronted and then beaten by Miki. Oga, Furuichi, Aoi and Nene arrive afterwards, having originally planned to stop Kanzaki. Nene identifies Miki as a Rokkisei. Miki tries talking to Oga, reminiscing about how close they were in middle school, but Beel starts yelling angry cries that interrupt Miki. Kazuya arrives and upon being asked, explains more about Miki: he says that Miki is the only first-year student to become a Rokkisei and that he's the captain of the karate club. Soon after, Miki starts mocking the delinquents of Ishiyama High which eventually drives Nene to try and attack him, though Oga manages to stop her. Miki leaves and tells Oga to come to the rooftop, as the other Rokkisei will be there. The delinquents leave but Oga asks Miki who he is, saying he doesn't remember him. Miki is silent.

In their classroom, Himekawa notes how they're being looked down upon. This angers Nene and she asks why he didn't do anything to help, adding further that even if the situation is meaningless to him he should have at least tried to protect his pride. Aoi then says that friends shouldn't fight though Himekawa questions about when they ever became friends. Aoi then notices that Oga is gone, to which Natsume states that he probably went home. He leaves and so does Himekawa, the latter stating that the situation is making him feel unpleasant at the school. Aoi watches as the three leave and tries going after them. At the rooftop, Oga meets up with four of the six Horsemen: Sakaki, Miki, Ichirō, and Hiromichi Gō. Gō is upset that Oga is the only one who came but soon afterwards, three others appear. These three are Himekawa, Aoi, and Natsume. They all state their reasons for coming and Gō comments that it's now four against four.

Meanwhile, Furuichi watches from the building along with newly-arrived Kazuya and Azusa. Kazuya identifies Gō for Furuichi, saying that the Horseman is the most violent person in the school and a member of the Amateur Radio Club. The battles between the four Rokkisei and four delinquents begin. The Red Tail watches as the eight teenagers fight. While the fight between Gō and Natsume does little damage to either, the battle between the Tōhōshinki and the two Rokkisei result in Aoi getting injured and Miki leaving the battle to fight Oga, who nearly defeated Ichirō in their own match. Miki manages to land a heavy punch against Oga. Aoi rushes to Oga's side, worried, and notes how Miki's attack is based on a martial arts that the military uses. Miki scolds her for interfering in his match but Aoi then lets him resume, remembering to put her faith in Oga. Much to her surprise, she then notices Natsume and Himekawa lose their own battles. Oga gets up from the ground and Miki tries to attack him again but is then kicked by Kanzaki. When Kanzaki tries to get Miki to fight him, Oga kicks the former and states that it's not their fight anymore. Oga and Miki then resume their battle until Miki attempts to use a secret technique but before he can use it, he is interrupted by an unknown female student. The girl is Shizuka Nanami, a member of the Rokkisei, who then starts to berate her classmates for involving themselves in the fight, adding further that "he" is very angry. Suddenly, another Horsemen named Kaname Izuma enters the rooftop and claims that he isn't mad. As Miki starts apologizing to Izuma, whom Kazuya mentions is the most powerful and feared of the Rokkisei, Aoi notices how the other male Horsemen are beginning to cower, as well. As she thinks to herself about this, Tōjō appears having been called out of work by Aizawa. Tōjō tries to start a fight with some of the Rokkisei but Izuma prevents any of them from joining him. Tōjō identifies Izuma as the leader and the apparent strongest, causing him to then punch the Rokkisei in the face. Izuma dodges, however, and Miki attacks Tōjō with the same punch that he used on Oga earlier. Tōjō is unaffected and Izuma offers to fight a death match. However, he then calls it off and tells Shizuka to handle everything else, to which she does. After talking to the other Rokkisei, Shizuka informs the delinquents about the police who are stationed nearby and Miki warns them not to mess with their school.

The next day, the delinquents find a list posted on the chalkboard about the students labeled for expulsion from the school: Oga, Furuichi, Aoi, Tōjō, Kanzaki, Himekawa, and Natsume. The said students are then sent to see Kido, who tells them that they are being expelled for fighting after they were warned. Furuichi tries to explain that he hasn't done anything but the teachers suspect him of being their strategist. Aoi intervenes and says that even if they are to receive the same punishment, the students at St. Ishiyama deserve no less. Kido informs them that the three students who attacked Shiroyama have been suspended for two weeks but the Rokkisei receive none, as they have high authority over the students. Kido also mentions that since the delinquents from Ishiyama have arrived, what the Rokkisei did is nothing wrong. This infuriates Aoi who proclaims that it's not fair; much to her surprise, the other students are fine with the situation. They state that since they're getting expelled anyway, there's no point in holding back anymore. As they're about to leave to find the Rokkisei, Kido stops them and says that if they do so, it'll only cause another uproar in the school. He then has a preposition: if the seven delinquents win a sports match against the Rokkisei in one month, they won't be expelled. Himekawa steps in and agrees to the plan, giving him and the others a chance to stay. Izuma then appears from under the window, telling Kido that he won't lose.

Meanwhile, Oga's class receives a new student: Hilda.

Preparing for the Match
Hilda sits in the seat in front of Oga. Aoi initially clashes with the Demon Maid because of Hilda's seating choice but the issue is eventually dissolved when the other delinquents' start questioning of a fight. As Hilda sits at her desk with Beel in her arms, she is then questioned as to how she was able to transfer to the school. She tells him how and adds that Alaindelon is also a new student, though he is with one of the St. Ishiyama classes. Suddenly, Yuka and Ryōko enter the classroom and inform the class that there will be a volleyball match during the school festival; the volleyball match will be the one played by Ishiyama and St. Ishiyama. The match shocks both the Ishiyama representatives and Miki, the latter wanting to have an actual fight against Oga. Izuma simply tells Miki that the two can have their own, private battle later. Later that day, Aoi is in the gymnasium with Oga, Baby Beel, Furuichi, Hilda and the Red Tail. Everyone (except Baby Beel and Hilda) are dressed in PE uniforms with several volleyballs beside them. Aoi is stunned by the lack of people and wonders why no one else is there, to which Yuka suggests that they lure the men there with their breasts. This plan is quickly dismissed and Hilda offers to help, stating that she will find a way to force the others into coming to practice. The next day, Aoi and the Red Tail arrive to practice and discover all the boys present and practicing.

It is later revealed that Hilda made Alaindelon transport all the boys into a white, spacious room during the night and had them watch a recorded video of the Rokkisei practicing during their match. The boys are initially uninterested but Himekawa suddenly requests Alaindelon to replay the video and increase the volume, to which it's revealed that the Horsemen are all insulting the delinquents. Furuichi notices that the voice-overs are fake but the others still fall for the trick, causing their spirit to be risen for the match. Meanwhile during their practice session, the boys start arguing about who is to be the captain of their team. Hilda then announces that whoever can match her powerful serve, which she'd just utilized against Furuichi, can be the captain. Aoi takes on Hilda's challenge. Hilda's first serve proves too fast for Aoi but the former Red Tail leader asks for another serve. Aoi figures out that she can counter the serve if she focuses on the sound and motion pressure around her, so she closes her eyes. She manages to return Hilda's serve but it hits the net; she is made captain, nonetheless. The MK5 suddenly arrive and state that they should be playing in the match, but they are easily beaten. As the group continues practicing, Himekawa is told that his pompadour is a distraction and when he refuses to change it, Yuka and Ryōka comb it down and discard his sunglasses; doing so resulted in Himekawa's appearance changing drastically to the point that people believe him to be a different person. They continue practice but Oga and Furichi have left, as well as Tōjō who needs to go work.

Oga, Furuichi and Baby Beel are walking home when they hear a loud noise coming from a nearby dojo. They look from the windows to see what is going on and find Miki in one of the rooms, training. Furuichi notices that there are sandbags scattered everywhere and that they're all ripped apart. Oga and Baby Beel enter the dojo and Miki decides to challenge Oga to a sparring match, to which Oga obliges to. Before their match, Miki asks why Oga betrayed him during the 7th grade from three years prior.

Furuichi thinks back to the incident that occurred during the three's younger years: three years ago, several months before the 7th grade would end, Miki would befriend Oga and Furuichi, looking up to the former. One day, there was an incident where Miki got into trouble with a delinquent named Reiji Kiriya and Oga protected him. Kiriya would eventually go after Oga, wanting revenge. During one of his attacks where Miki tried to help Oga, the latter attacked Miki under the claim that they didn't even know each other. Afterwards, Miki would leave the school and move to Nara with his mom, though this was planned originally.

Oga and Miki then begin their fight. Oga taunts Miki for not using his special techniques, provoking the latter into doing so. Miki starts using fighting moves such as Senbukyaku and Sōdashō. He says that he's training himself to get stronger so that he can fight Oga before using another technique, Sōtenshu. However, Oga is almost unaffected by these moves and tempts Miki into getting serious which he does. Miki takes a stance, the same one he planned to use against Oga in their last fight, Meiōsatsu. Oga is defeated and he leaves, along with Furuichi and Baby Beel.

Afterwards, they go visit Tōjō at work where Oga challenges the Senior to another fight. Tōjō leaves work and goes to the river with Oga, Furuichi and Baby Beel. Tōjō figures out that Oga probably lost a match with someone, which Oga replies that he did and explains how his fight with Miki ended. Oga then asks how Tōjō was able to handle Miki's ultimate attack without flinching but Tōjō doesn't reply, instead engaging into the battle. As they fight, Tōjō notices how Oga seems to be getting weaker. They continue their battle and Beel announces Oga as the winner, much to Tōjō's chagrin. Oga shrugs it off, however, and says that for him to beat Miki he needs motivation. He then vows to beat Miki, whether its a real match or a sports match.

Game
Two weeks later, the festival begins. During the festival, several thugs from Teimō Tech have arrived and the Rokkisei wonders if they're here because of the Ishiyama delinquents. As the thugs are walking around the festival, Kazuya spots one of them and notes how he's not bald like the rest. In the meantime, Aoi is with the Red Tail in their classroom, all dressed in their PE uniforms. Aoi remarks angrily how the boys are late. She is then told about Furuichi, who's currently at the Maid Cafe in Saint Ishiyama Academy. Furuichi is ordering various items from the menu while female students surround him, including Hilda. Hilda and Furuichi talk to each other, mainly about Oga's whereabouts and Alaindelon, before Hilda asks if Furuichi should be getting ready to play the match. Furuichi states that he's only a substitute so it shouldn't matter but Aoi hears him and tries dragging him away. Before they leave, they see a thug from Teimō Tech harassing one of the female workers at the Maid Cafe, to which Ichirō comes to the student's defense. Afterwards, he and the other Horsemen defeat the other thugs except for Miki, who's still injured from his fight with Oga. Meanwhile, Oga and Miki meet each other just before the match, Oga stating that he's developed a new move. The two then return to their volleyball teams and each team proceeds to the volleyball court. It's revealed that the boys on Ishiyama's teams (except Furuichi) have all overslept that morning.

Izuma starts off by thanking the delinquents for making the festival more exciting this year and shakes hand with Aoi, causing several girls in the audience to start their booing. Shiroyama then appears, fresh out of the hospital, cheering for Ishiyama along with the Red Tail. Lastly, Oga is asked about whether he should let Beel ride his back during the game but the issue is quickly overlooked as it's not against rules and everyone doesn't mind it, with Miki even adding that Beel was like a part of Oga.

The match then begins. The match starts well for both sides until Team Ishiyama plays a foul, something that Tōjō and Oga caused when the latter kicked the ball instead of using his hands. Team Ishiyama then calls a timeout so that their team can discuss the rules with Tōjō and Oga, both of whom were almost never at practice. During the timeout, Himekawa discusses various "loopholes" regarding the game. The timeout is over and the game resumes. Oga uses a tactic where he tricks Team Rokkisei into believing that Beel is a volleyball while Himekawa gives them a point. Beel is then continuously used throughout the rest of the match, eventually giving them a 24-21 win in the first set. But then, Izuma launches a powerful serve at Aoi that surprises her. By the end of the set, Team Rokkisei manages to win and Aoi suffers burn marks on her arms. Furuichi then substitutes for Aoi in the next set, but Team Ishiyama begins suffering major losses. Meanwhile, Aoi and Hilda start talking about Izuma but Hilda's words confuse Aoi, causing her to think that the topic is on Oga. As they continue to talk, confusing each other as the conversation continues, Aoi remembers how Team Ishiyama can get expelled and how she doesn't want that to happen. She gets up and decides to resume her position on the team, proclaiming that they will win the match. As Izuma serves, Aoi manages to return it, saying that Hilda's serve is more powerful. As the match continues, Team Ishiyama gradually gets better and starts receiving much support from the audience. By the end of the game, Oga lands a winning score for Team Ishiyama and they win, thus preventing them for expulsion.

Revenge of Teimō Tech
As the match has just ended, the announcers are suddenly attacked and a male student from Teimō Tech grabs the microphone. He compliments on the match but says how disgusted he is in Oga, as he never expected for Team Ishiyama to be playing a match in volleyball or to even transfer to St. Ishiyama, no less. The delinquent is then revealed to be Reiji Kiriya, also known as Viper, the same delinquent from Oga's, Furuichi's, and Miki's past from three years ago before Miki moved away to Nara. Kiriya states how he's been waiting to get his revenge on Oga, who wounded him with his own signature weapon. Oga ignores this and tries passing Beel off to Kiriya but the strategy ends up failing, as Beel simply stomps on Kiriya. Kiriya then says that this is an act of violence (as Oga helped Beel stomp him) and demands that Oga be expelled. This is excused but Kiriya continues to provoke Oga, knowing that he is the type of person who doesn't hold back. Kiriya then keeps beating Oga, ignoring his own possibilities of expulsion, but Oga doesn't attack as it'll ruin his and Team Ishiyama's efforts to stay in the school.

Having had enough, Miki then attacks Kiriya and asks if the latter remembers him. After looking at him, Kiriya then recognizes Miki and goes on to answer one of Miki's earlier questions, replying that after the incident from three years ago, he'd moved to Nara with his family. This shocks Miki who then thinks back as to Oga's words from before, wondering if Oga's "betrayal" was actually a setup to protect him in the future. Suddenly, Miki is struck down by Teimō's Shadow Force whom Kiriya remarks are late. Miki tries to attack the Shadow Force but is easily beaten. Oga then steps in and defeats two of them, saying that he'll clean up the trash before saying Miki's name. Miki is shocked and gets up, telling Oga that if he remembers his name then he should call him by his first name, instead. Oga objects and says it's creepy. They then witness members of the Shadow Force getting up with little injuries, to which Kiriya states that they're the strongest in his school. Aoi and Shizuka then try to help the two males but are stopped by Izuma and Furuichi, who remind them that it's their fight and that the rest of the school is being held hostage. However, Kiriya's plan starts turning awry. Miki and Oga dispose of the Shadow Force while Team Ishiyama and Team Rokkisei free the hostages. Oga then turns to Kiriya, frightening the delinquent, and uses Zebul Blast with Be'el to defeat Kiriya. Oga's body is left with heavy tattoos, due to his Zebul Spell marking seal. He also charcoals much of the gymnasium and tells Kiriya that he has three minutes to leave with the rest of Teimō Tech. Kiriya, scared for his life, leaves screaming.

Everyone is shocked and confused by what had happened, with almost no one recognizing Beel and his electric shocks. Hilda and Furuichi are the only ones who remember. Even Izuma recognized Beel as a Demon, a member of the Royal Family, too. He then devises a quick scene where everything was said to be an act, convincing almost everyone with it including the teachers. With everyone convinced and everything seemingly normal again, Izuma tries to leave but not before warning Oga on overusing his Demonic powers. Oga discusses this with Hilda and Alaindelon on the school rooftop, with Aoi listening. Everyone else either goes home or relaxes, all content that they're still going to stay in the school.

Meanwhile, a mysterious man arrives at Saint Ishiyama Academy thinking about how the festival is bringing back old memories. With his jacket held over his back and the mysterious Crest of the Royal Family on his arm, the stranger from Tōjō's past wonders if the delinquents are causing trouble at the school.

Manga and Anime Differences

 * Even before the Prince En Arc begins, En and his Demon Maids make brief cameos in Episode 26 and Episode 36.