Shintarō Natsume

is a carefree, easy-going underling to Hajime Kanzaki. Despite being a delinquent, he rarely participates in fights and prefers to stay out of them. However, he is a very capable fighter on a level comparable to even Kanzaki himself.

Appearance
Natsume is shown to be a tall, mildly muscular individual with neck-length brown hair and matching eyes. Natsume has also been shown as being handsome. He commonly wears a hoodie when not in school uniform.

Personality
Natsume is an extremely laid-back and mysterious character. He normally displays mild amusement to most situations, even dangerous ones other characters are serious about. He likes to keep tabs on people he finds "interesting" such as Kanzaki at first and then later Tatsumi Oga. He seems to have some sort of hidden agenda as while he is technically an underling of Kanzaki, he has displayed strength that far surpasses the other delinquents, having been able to single-handedly defeat the MK5 and fight on equal terms with a member of the Rokkisei, without putting in any effort. In an extra episode of the anime, Himekawa stated that Natsume had no need to follow Kanzaki, and Natsume answered by saying that he only did it because it was fun since Kanzaki was so active.

Tōhōshinki Arc
He first appeares with Hajime Kanzaki and witnesses his defeat by Oga. After that, he takes a keen interest in Oga's affairs. Oga and Natsume meet again in a supermarket where Natsume works part-time and he tells Oga that he just defeated one of the Tōhōshinki and that there are three more Oga must contend with if he is to become the strongest delinquent in Ishiyama High. Natsume then appears in the middle of Oga's ongoing confrontation with Aoi, witnessing Nene and Chiaki confront Oga about Aoi. He defeats the MK5 all by himself when he learns they ganged up on Nene and Chiaki, dealing with them while Nene warns Aoi that they were set up by Miwa to fight Oga. During Oga's battle with Tojo, he saves Kanzaki and Himekawa from Aizawa and Jinno's attacks, and also ends up helping them out of the Ishiyama building explosion caused by Oga. Out of all the students who were involved in the explosion, Natsume was the only one to escape uninjured.

Saint Ishiyama Academy Arc
Natsume defends Oga from an attack by Hiromichi of the Rokkisei. They had a reasonably matched fight, but only because Natsume pointedly claims he held back. He is one of the seven Ishiyama students who played in the volleyball match against St. Ishiyama to avoid expulsion.

Prince En Arc
Natsume is part of the team that plays video games at Himekawa's apartments to help locate En. He also went to the store to get food for everyone along with Lamia and Furuichi where they encounter Yolda and find out they've been playing next door to them all along.

Akumano Academy Arc
Natsume, along with the other Ishiyama students, train under Zenjūrō Saotome for the upcoming fight with Akumano Academy. He is shown to be fighting against Kanzaki to a standstill during the training. Later, Kanzaki's gang with Izabella arrive at Akumano Academy to complete one of Quetzalcoatl's games required for Oga to continue. However, the game is interrupted with the arrival of Lindworm.

Mobichi Arc
Natsume accompanies Kanzaki while he goes to look for Furuichi and have a rematch with him. When they find him, Natsume laughs at the circumstances.

Saint Saint X'mas Arc
Natsume stands amongst his fellow delinquents in their homeroom at Saint Ishiyama Academy, smiling happily. He listens to Yuka explain to them about how the "real" Santa Claus is going to come visit after the Saint Saint X'mas competition on Christmas Eve.

On Christmas Eve, Natsume attends the competition to watch as one of the spectators. When Kanzaki and Yuka are entering their first round, listening to the explanations for their event, Natsume yells out at them to do their best. He then continues to observe the two as they participate with their match. Natsume expresses surprise at when the two fail to progress over a mutual embarrassment, later showing excitement when they start to do so, though he ultimately laughs in discomfort as he watches Yuka strike Kanzaki because of her mixed feelings.

Later, Natsume laughs that the match for Izuma's and Aoi's second round could possibly be too much for the "sheltered queen" to handle.

Return to Ishiyama High School Arc
Kanzaki, Natsume and Shiroyama meet together on their first day back and take a stroll in one of the building hallways. Natsume notices Oga and Furuichi, casually greeting the former. He then remarks on the apparent rise of powerful first-years in Ishiyama and warns Oga, knowing that he is a primary target. Oga responds by taking down a delinquent who was sneaking up behind the three older teenagers, which surprises them. When he leaves, Natsume and Kanzaki note on his evident confidence about the matter, though Natsume mentions that he will be in serious trouble should he be too careless.

Later, Natsume and Kanzaki hear a crumbling noise behind them. The same delinquent previously buried in the concrete wall manages to break free, albeit with a large chunk of the building stuck around his neck, and he playfully introduces himself as Yōhei Nasu to the elder students.

Nasu soon engages in a battle with Kanzaki, easily overpowering and defeating the Tōhōshinki; such a remarkable strength astonishes Natsume and Shiroyama alike. The latter rushes over to Kanzaki's side, but he is stopped in his tracks by Misao Onizuka, whom Natsume vaguely remembers from long before. Natsume is forced to watch as Onizuka taunts the power of the Tōhōshinki before then knocking Shiroyama down; before he can continue any further with Shiroyama, he is stopped by Natsume. Onizuka mocks Natsume for always being calm and level-headed as he aims to punch him. Natsume easily grabs his fist with one hand, even forcing the older student on his knees while trembling; while he does so, he points out to Onizuka that he is actually very pissed. Nasu witnesses Natsume's surprising act of intimidation and requests that they go head-to-head. Natsume refuses saying that only the "general" should do so; with that said, Oga and Baby Beel finally appear.

Natsume then puts himself on standby seeing as the child-rearing gang leader has made his entrance. However, he does express shock when he sees Oga being seemingly taken out in one hit; worried that Nasu's power has been underestimated, he concludes that the "Killer Six Elements" in the high school have risen. Eventually, two other delinquents named Ebian Ichikawa and Kankurō Akahoshi arrive to take down Nasu, resulting in a brief threesome battle.

Later, Natsume notices a large man ready to club Kanzaki's head with a massive drumstick; upon seeing this, he immediately warns for Kanzaki. In the end, only Shiroyama is hit, and Nasu leaves with other Poltergeists, which includes the large man who had tried to attack Kanzaki. Nasu gives a final warning before leaving that everyone who came back from Saint Ishiyama will be brought down, including Oga, and that Baby Beel will also be taken away. Shortly after, Ichikawa and Akahoshi leave with similar messages. This leaves Natsume and the others alone in the hallways as they reflect on the newcomers' words.

Natsume later heads to the Kunieda residence with several of his classmates; when gathered around, he suggests that anyone not present has already been defeated by the first-years. The group soon begins discussing about the "Killer Six Elements". Regarding Nasu, Natsume states that he is unpredictable yet a very powerful threat; therefore, they will all need to be more cautious towards him. Eventually, the delinquents figure out their plan. Furuichi suggests that they gather information on the Poltergeist's activities which Natsume readily agrees with. Then, following a leadership dispute, everyone partakes in a game of rock-paper-scissors to determine the leader in their alliance, which turns out to be Baby Beel.

The following day, Natsume waits in the corridors of one of the school's buildings, hiding behind a support pillar as Teruomi Hino and Taizō Shioiri walk by. He informs Kanzaki and Furuichi about his sightings and reports back that they appear to be heading back towards the other Poltergeists. Natsume notes that there will be a bad situation if they do.

Natsume goes to play tennis with his classmates several days later. While everyone is talking about Himekawa, he remarks that the Tōhōshinki is impressive for being able to make multiple accomplishments in such a short amount of time. Natsume maintains a cheerful attitude as he continues to play tennis, even when facing Furuichi or Tōjō. Even so, he listens further to his classmates' discussion about their Takamiya's takeover of the school.

Late at night, Natsume and several of his classmates from Saint Ishiyama Academy head to their high school; as they arrive, Natsume reminds everyone that they cannot be at home sleeping while Oga and Furuichi are fighting.

Upon arriving, they are approached by the members of the Himekawa Special Forces, surprising Natsume; when he sees a mysterious tattoo and number appear on all of their bodies, he becomes slightly confused, especially after sensing their boost in power. Later, he hears a loud sound ring across the campus and looks up for it. Natsume then watches on as Kanzaki arrives to save them, showing an expression of happiness and relief upon seeing his superior.

Powers & Abilities
Natsume is shown to be one of the strongest and is rated to be on the same level as Hidetora Tojo by Onizuka Misao a guy who went toe to toe fighting with Tojou for three years in Ishiyama. It is assumed he could even crush Kanzaki and Himekawa if he wanted to and is also capable on crushing Hiromichi Gō of the Rokkisei who is a mixed martial arts second-year champion. However, the true extent of his abilities is unknown since he is rarely seen fighting, and when he does fight, it is never at full strength. He is mostly seen using kicks as his main fighting technique.



Quotes

 * "It's not really my style to go all out in a fight" - When fighting Gō.
 * "Ah, but Kanzaki-Kun is a tsundere." - Commenting on Kanzaki's personality.
 * "So I'm always smiling...? I'm actually quite pissed right now." - When fighting Onizuka Misao.

Trivia

 * Natsume has light-brown hair and eyes in the manga, while they are portrayed as purple and black respectively in the anime.