You Adachi

Adachi's delinquent younger brother. Like Adachi, You has excellent fighting abilities and is capable of taking on the boys of Mon Shiro's Student Council on his own. However, unlike his sister, You is an all-around genius. He both fears and admires his sister, and his goal was to conquer the nation with her, but she had left the main house and put her delinquent days behind her. He too leaves home and attempts to live with Adachi, but after she refuses, he starts living with Shinagawa. He has a sister complex. (Source : Wikipedia)