Serizawa, Aiko

芹沢愛子

She was a classmate of Sakamoto and Oda. Sakamoto harbored feelings for her, but Oda seduced her and took her away from him.
Aiko only appears in the narrative within Sakamoto's high school flashback. In that memory, she is the object of his affection. Although he loved her, he lacked the courage to confess his feelings. After Sakamoto shared his feelings for Aiko with Oda, Oda insulted him, calling him naive and an idiot. Oda explained that if Sakamoto remained too passive, Aiko would end up with someone else. Later, Oda had sex with Aiko after she confessed her feelings to him. When her friends and Oda's girlfriend discovered the affair, she burst into tears out of guilt, and Sakamoto attacked Oda, partly because of Aiko. She has not been seen since.