Aku has an ability called Rashoumon where he can manipulate his clothes into tendril like weapons. He's powerful but doesn't think so. He tends to come off as cold and uncaring but is actually sweet when you get to know him, though he's likely to hide romantic feelings since he doesn't like being seen as vulnerable. Surprisingly sassy. Greatly cares for Dazai's approval. Also has a disease that makes him cough occasionally that he often goes to the nurse for but it's nothing serious. Tsundere.