Hinako is unhappy about her father Ichiro's sudden remarriage and complains about it to her classmates Mami and Atsushi. However, Hinako's only pleasure is peeking at her parents' intimate moments. After accidentally witnessing something, she finds herself heading to her parents' room every night. Shortly after, her mother, Nobuko, is called to Hinako's school for a career counseling session and realizes that the homeroom teacher, Nishioka, is her ex-boyfriend who abandoned her years ago. Hinako, however, remains oblivious to the turmoil in the lives of both of them…