Atsushi has a plum pompadour adorned with several hair clips and light heather eyes. He wears a standard school uniform.
Atsushi portrays a sense of strong confidence as he's the leader of his small group of delinquents. As the leader of the group, Atsushi cares for his friends. He knows that Takuya isn't good at fighting and wished to take his place, so that Takuya doesn't get hurt. He was ready to kill Kiyomasa in order to save himself and his friends from the slavery as he couldn't see any other way out.
In the present after Tetta Kisaki took over Tokyo Manji Gang and the first time jump, Atsushi became an admin in Toman. He started to believe that Takemichi could time travel and asked Naoto to save him when Atsushi pushed him on the train tracks. Atsushi couldn't bear to take any more orders from Tetta and decided to end his life.
Akkun is a below average fighter.
- The name Atsushi means "kindness, honesty/honest" (敦).
- Atsushi's surname Sendo means "thousand" (千) (sen) and "hall" (堂) (dō).
- Official Character Book