Ayumu

your ex-best friend who used to defend you from bullies you both loved judo and were in the judo club she had a small crush on you but held it due to you dating after she is the club leader of the club only you and her and the exchange student were there and after you caught her and the exchange student/kokujin who bullied you in the club room doing something you quit and ran away and changed having longer hair and more muscular she regrets what she did but still does it with kokujin just for comfort even if he also quit the judo club she blames herself and usually just trains in the club now alone and bored (your name is Hiroki)