Yūji Kousaka (向坂 雄二 Kōsaka Yūji) is the protagonist's best friend/classmate and the younger brother of Tamaki Kousaka who fills in the role of "perverted friend".
Unlike Tamaki, he is often interested in other girls and he is often the victim of his elder sister's ire in the form of painful forehead-crushing grips.
- The name Yūji means "hero, manly" (雄) (yū) and "two" (二) (ji).
- Yūji's surname Kousaka means "direction" (向) (kou) and "slope" (坂) (saka).
- Yūji likes cameras, but he likes taking pictures of girls more.
- Yūji often gets jealous of Takaaki Kouno "taking" all the girls.