Field Trip Arc

The Okinawa arc is the seventh story arc in Beelzebub. It consists of Chapters 148 to ongoing, beginning with the introduction of Kanzaki's niece, Futaba. Afterwards, the arc then transitions to Okinawa, Japan where the students of Ishiyama and Saint Ishiyama are currently taking their field trip. In the new city, they find themselves at odds with a local school called South Chinpira High School.

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

Babysitting
Hajime is lounging on the couch at his home, reading a magazine. His little niece starts pestering him to play with her. He ignores his niece and continues to relax. Hajime thinks to himself about how a "mischievous little ghost" has been haunting him since the Akumano Academy invasion.

In the meantime, Hilda has prepared dozens of croquettes for Oga but he refuses to eat them due to their unpleasant appearance. Hilda says that it's a token of thanks to Oga since he's saved her before several times in the past. He continues to refuse the croquettes and Hilda expresses her anger at him for insulting her cooking. They have an argument about Hilda's cooking which is quickly dissolved when Oga's family returns to the house. His family, mainly Misaki, is disappointed in the return of Hilda's memories. Oga's Mother tries to explain to Hilda about when she had amnesia but the Demon Maid doesn't remember anything from it. Oga feels relieved somewhat, as he thinks that she would've done something drastic if she remembered anything about her past. Hilda turns to Baby Beel and notices how much he's "changed" since they last met before hugging him affectionately (not wanting to "lose" to her former, amnesiac self).

Furuichi and Lamia talk outside about Hilda's memories returning. Lamia theorizes that Hilda's former, innocent self was actually another side of her and that it may come back in the future. She then tells Furuichi that she's hungry and they walk together. Oga decides to go out to the corner store with Baby Beel and Hilda accompanies him. Oga asks if she's always going to be around him and Baby Beel, to which Hilda answers, and reminds him that he chose to become her master's parent. Upon hearing this, Oga says that he's not going to let Baby Beel destroy humanity and Hilda replies by saying that, because she serves Baby Beel, she won't destroy humanity if he decides not to do so. She adds by saying that she wants the Demon Lord to be the best that there is and how Oga is only one who can help him.

The next morning at the school, a morbid-looking Kanzaki decides to talk to Oga and asks if he can babysit his niece, whom he was instructed by his family to look after. When Oga refuses, he angrily says that Oga needs to repay him for helping save Hilda, but Hilda insists that he should help because she sees Kanzaki as another "peasant under Baby Beel's rule". Nevertheless, Oga goes and brings a reluctant Furuichi to help.

Oga is quite stunned by how extravagant Hajime's home is, mainly with the underlings that follow him. Hajime leads Oga's group inside his house, which also serves as headquarters for a Yakuza-based group that Hajime's father Mugen heads. Hilda initially has conflicts with Mugen when he claims that his granddaughter Futaba is cuter than Baby Beel. Hajime tells his father not to be embarrassing himself and even full-out tells him how Futaba doesn't really like him. When Mugen starts crying out in confusion, a young girl kicks him in the back for being so loud and yells at Hajime for making her hide from her grandfather too long. Hajime says that the girl acts this way because Mugen spoils her and this is further proven when she asks one of Mugen's underlings to act like a horse for her to ride on. Oga, Hilda, and Furuichi all note how she's actually more bratty than spoiled. They go to Hajime's room with him and the young girl is properly introduced as Futaba. After some insistence from the others, Furuichi tries reasoning with Futaba by pointing out her flaws but she couldn't care in the slightest. Oga then does the talking and starts off with Futaba's actual strength. He asks if she can back-up the claim that she does the bossing around with her underlings. This draws Futaba's interest but the topic is quickly brushed off when Oga claims himself to be the strongest person she'll ever meet.

Hilda then uses Baby Beel to talk to Futaba. However, Futaba becomes interested in Baby Beel and makes him her lackey. Because he cannot keep himself composed because Futaba is a girl, Baby Beel cannot seem to refuse her even with just random babbling.

Futaba decides to take Baby Beel with her, bringing along the others with him. Hilda starts scolding the Demon Lord for listening and obeying Futaba, but then Futaba starts insulting Hilda by calling her an "old hag". Baby Beel tries to play peace-maker between the two but to no avail. Eventually, Futaba decides to have a little showdown at the river and brings the gang with her. Her choice of battle is revealed to be a round of stone skipping. She manages to score five skips but Oga cheats and uses Demonic magic to skip his rock to the other side of the river.

Futaba then gets Kanzaki to throw the rocks for her and he decides to participate, telling Oga that he's not the only person who went through Saotome's training. Kanzaki, using elements of nature around him, skips the rock and it starts making way for the other side of the river, much to the others' shock. But then a catfish gets in the way and Oga wins the round. But Futaba won't admit defeat and even starts crying. As Oga keeps taunting her, Hajime punches him for making Futaba cry. Oga then says that he leaves everything else to Hajime, confusing him, and leaves with the others.

Field Trip to Okinawa
During a class session for the Ishiyama students, Saotome informs everyone about how the students from Saint Ishiyama will be heading to Okinawa for a field trip within two days, and how they're going to be following them there. Furuichi asks how their class can go when they don't have money and have students from varying grade levels. Despite having his own concerns of the matter, Saotome insists that they go because it's extremely rare for Ishiyama to host field trips anymore. The students are unimpressed, almost indifferent to the whole idea of a field trip. But Saotome, determined to go on the field trip himself, says that if he wants to go then they'll have to go as well. Furuichi starts supporting the idea of going to Okinawa after realizing how the beaches there should be clustered with attractive women in bathing suits. Ignoring Furuichi's fantasies, the other students start thinking about how fun it might be if they actually go to Okinawa. With this, Saotome and several male students decide to talk to Kido and discuss the inclusion of their class in the trip. Kido points out several reasons why they can't go. Saotome starts thinking about talking with the principal, saying that he wants the field trip to be a great experience for his students.

Saotome starts organizing a plan with their students. He decides on a scheme where they divide into three groups and attack the principal from three different points. But after a personal talk with Saotome and Genma, the principal decides to let Ishiyama join in on the field trip.

The two schools then leave for the trip after two days of waiting. A student from Saint Ishiyama begins to take role call of the Ishiyama students but takes Ichirō with him, so that the Rokkisei can handle the complaints regarding them. Ichirō walks around Ishiyama's compartment and sees how varied the atmosphere is among the students. He then decides to speak to Aoi, the class representative, and learns that the class did actually have permission to join the field trip. Ichirō then returns to his own compartment and asks that the Ishiyama students don't disappoint his fellow classmates.

The plane eventually lands in Okinawa and Furuichi starts basking in the pleasant atmosphere, happy to be away from Alaindelon (though much to his dismay, the Transdimensional Demon arrives anyway to hand him some underwear). The students, both Ishiyama and Saint Ishiyama, then leave for their hotel. As they arrive, another school called South Chinpira High School arrives and spats on a sign that reads their school name, the one that shows Ishiyama's inclusion as guests in the hotel. The students from South Chinpira start harassing female students from Saint Ishiyama forcing Ichirō and Mitsuteru Sakaki to take action. However, the two Rokkisei are quickly outnumbered. The male students from Ishiyama then get involved and start brawling with the delinquents from South Chinpira, who are shocked by how strong Ishiyama is.

At that moment, a "child-rearing gang leader" from South Chinpira arrives at the hotel with a young baby on his back, complaining about the bus service. He tells his fellow students not to bother other schools before flicking one with his finger, sending him crashing into a support pillar. This surprises several bystanders, including the students of Ishiyama and Saint Ishiyama. The apparent leader of the South Chinpira students apologizes about his school to Oga, then introducing himself as Aiba. He also notices that Oga has a child on his back, like himself. He asks for Oga's name but he replies by calling himself "Madason" (a reference to Dragon Quest 5) Worried that something might come of it, Aoi intervenes and apologizes in Oga's place for his behavior. Aiba becomes interested in Aoi and accepts her apology, but then asks about her relationship with Oga. Aoi denies a relationship between the two. With this, Aiba fully introduces himself as Izō Aiba and begins flirting with her. He then asks for her name, causing Nene to hit him for being too forward. Aiba then learns Aoi's name and decides to leave, giving her a pleasant goodbye and another to Oga. The students of Ishiyama then head to their respective rooms and get comfortable with the living situations.

Sometime later, Oga and Aiba meet again in one of the hotel's hallways. Aiba asks for Aoi's room but Oga refuses to tell him. Eventually, the baby girl on Aiba's back falls in love with Baby Beel after she saw him, causing Oga to exasperate at how emotional Aiba's group supposedly is. The two delinquents head to Aoi's and the Red Tail's room where they learn that Chiyo, Aiba's younger sister, is actually attracted to Baby Beel because of his male reproductive organ. In the meantime, Nene is displeased that Oga and Aiba had barged into their room, especially with Aiba. Aoi asks why Chiyo joined her brother on the field trip and she explains how she, a passionate activist on books and fortune-telling, found in a horoscope that she would have an encounter on a southern island. Chiyo then asks for Aoi's astrological sign. Aoi reveals that she is a Taurus and Chiyo discovers that she has a high love compatibility with Virgos. It's then revealed that both Aiba and Oga are Virgos themselves. Nene decides to move the topic elsewhere and tells Aiba that Ishiyama doesn't want to fight with South Chinpira, and that it's probably vice-verse for him. Aiba admits that he doesn't want to fight either.

Hilda, dressed in her school uniform, learns from Furuichi that Oga took Baby Beel with him. She then meets the Red Tail (aside from Nene and Chiaki), who were on their way to the baths. They become interested in Hilda's and Oga's life together and bring her to the baths with them but are disappointed with what they learn.

Around the same time, Kanzaki's group, which includes Futaba, go outside so that Kanzaki can buy "yogurti" which is supposedly a limited item. When they find a vending machine, they encounter delinquents from South Chinpira which includes their own version of Ishiyama's Tōhōshinki group. After defeating South Chinpira's Tōhōshinki, more students from Aiba's school arrive and surround Kanzaki's group. The students attempt an attack on Futaba which angers Kanzaki, but they manage to capture her anyway. Tōjō and his group arrive and decide to help out Kanzaki.

Thinking about Aiba's words, Aoi considers eating with Aiba during the next day. Aiba excitedly agrees to the offer but Aoi quickly changes it around, suggesting that Oga should go with them. Hesitantly, Aiba allows it.