A tbhk x kny au

Amane yugi, a 13 year old boy who is a quiet but cheerful student that attends Kamome Academy. He has a younger twin brother, Tsukasa yugi. Tsukasa is clearly more cheerful and has more energy than amane. One day during winter break, Amane goes to run an errand for his family. While he did what was asked, but once he got home he finds that something attacked them while he was gone. The only one who survived the attack was Tsukasa. But something is off about him now.

TBHK BELONGS TO AIDA & IRO
DEMON SLAYER BELONGS TO KOYOHARU GOTOUGE