Ritsuko calls Aono to ask for a favor. She wants to give him a performance of Bach's "Concerto for Two Violins," Aono's mother's favorite, as a birthday present. Just like in middle school, Ritsuko tutors Aono, and Aono teaches her violin. On his birthday, Aono is excited to visit a girl's room for the first time. Ritsuko's mother is curious about Aono, whom she's meeting for the first time. The two begin playing. The sound of the violin holds special meaning in the relationship between Ritsuko and her mother.
