Yūichi constantly sneaks out at night, and to cut his habit, his nurse Akiko barricades his door to prevent him from leaving. However, she strikes a deal that if he is able to become friends with a new patient, she will lift her restriction. The new patient turns out to be Rika, a seventeen-year-old girl in the eastern ward who enjoys reading the works of Ryūnosuke Akutagawa. At first, Yūichi, with the assistance of Akiko, lies about reading the same book, but Rika easily sees through this act and demands that in exchange for her forgiveness, he must do what she wants. One day, Rika requests to go up to Mount Hōdai despite her weak, sickly condition because it was the same place her father hiked up before he died, and she believed if she is able to do the same, she will lose her fear of dying. Yūichi sneaks her out of the hospital with much success and realizes that he is doing favors not because she tells him to, and when he tries to tell her his true intent of assisting her, he faints.
高校2年の冬、突然の肝炎で入院することになった裕一。病状は軽く、夜中に病院を抜け出しては看護師の亜希子に怒られていた。そんなある日、裕一は亜希子から、転院してきた女の子の話し相手になってくれと頼まれる。亜希子もその子の扱いには手を焼いているらしい。恐る恐る女の子のいる病室に入る裕一。そこには長い黒髪の美少女、里香がいた。