Diablo (ディアブロ) is a mystical creature that belongs to Shimotsuki Shun.
He has no specific shapes so he is seen as/possessed a red box of tangerine (mikan). The only person who knows his true form, be able to open and help him changing boxes is Shun.
- He is brought from hell to the dorm by Shun.
- People say if another person beside Shun opens the box, the world will be destroyed.
- Many delivery men were scared by him.
- Sometimes when Diablo plays near the dorm's door, delivery man thinks he is meant to be sent, so he is taken away.
- He was presented as a cabbage box.