Kaoru Tsutsui

The younger brother of Tsutsui, who is the classmate of the younger sister of Tsutsui's bully Mitsuya. Tsutsui does not have a very close relationship with his brother, Kaoru. There are times when Kaoru seems to "secretly" encourage Tsutsui when suggestive things happen in Tsutsui's room with Iroha, although Kaoru does not have much faith in his brother. In a time of major duress, Kaoru thinks of the damage to his own reputation instead of rallying to his brother's aid for support, and explicitly mentions that he does not want to grow up like Tsutsui.