Hiroko has Kōsei critique Nagi on her technique during her piano lessons. After Kaori surprises Kōsei with a shopping spree at a department store, he assumes that she left her backpack at the school since she was wearing her school uniform, but he realizes that she was lying about it. As Kōsei takes Kaori home on a bike, she tearfully thanks him for spending time with her. Nagi begins to plot revenge on Kōsei after he continues to point out all of her mistakes during her piano lessons. One evening, as Kōsei finds Nagi at a stairway to a shrine, Nagi admits that she looks up to her older brother, whereas Kōsei reveals that he looks up to a girl that he can never date. In the hospital again with her friends, Kaori becomes so upset that Kōsei is spending less and less time with her. Meanwhile, Nagi feels like she and Kōsei are two of a kind, chasing the one person that they cannot catch up with. Kaori proposes a double suicide with Kōsei.