Yuusuke Asahina

The eleventh son of the Asahina family. He is a delinquent who happens to go to the same school as Ema and coincidentally is her classmate. He has a righteous personality and hates anything to be incorrect, despite also being a delinquent. It is revealed in episode 2 that he was already having a crush on Ema at school, even before she became his sister. He was very confused when she was accepted in the family. His goal is to enter Meiji University with Ema.