高中女生纱夜在一次交通事故中失去了父母之后,就寄居在姨妈“秋”家里。同时纱夜和她的同学玲奈成为了朋友,并慢慢地敞开了心扉。然而,秋患有早老性痴呆症,她的记忆开始模糊。纱夜也与玲奈发生了争吵,她对自己不幸的生活感到愤怒。最后,当纱夜发现了秋的秘密后,开始认识到了一点生活的意义…… Saya, a high school girl, loses her parents in a traffic accident and lives with her aunt, Aki.Saya starts spending time with her classmate, Reina, and Saya slowly begins to open up.However, Aki continues to suffer from juvenile dementia. S......