Kazuki Kohori
A young student who works part time with Risa in Ikebe. He is notably shorter than her, although slightly taller than Otani (158 cm.), and has distinctive black hair with a red streak. Risa soon discovers that he is also an avid Umibouuzu fan. He very soon develops feelings for Risa, who admits to herself that she finds him 'cute'. Against her better judgment, Risa attends an Umibouzu concert with Kohori which leads to her temporary breakup with Otani. He even tells Ōtani that he is in love with Risa, which causes Ōtani to slug him.