Sakamoto's former bully, and one of a three-member delinquent group. After being bested by Sakamoto, Acchan no longer smokes, instead choosing to blow bubbles.
He harbors both resentment and admiration to Sakamoto and during the third year students' graduation ceremony, he was manipulated into attacking Sakamoto while he delivered a speech. Eventually, he gives up and voiced his jealousy towards Sakamoto and the latter cover up his attack as a part of his speech, saving him from disciplinary punishments. After Sakamoto announced his departure to America, Atsushi announced his dream to study harder and surpass Sakamoto while trying to throw a cream pie at the former before he evades.
