藍沢日向は、椿が丘高校のスクールカウンセラーとして、最後に味方になってくれる大人の立場で、学校や家庭に悩む生徒の心のケアに日々励んでいる。一方、ブライダル会社に勤務している本庄和彦とは3年もの間恋人関係にいるが、一度も母・尚子を会わせていない。ある日、夏休みの途中から不登校を続けている1年B組の生徒でバスケ部員・吉岡圭吾の自宅に担任の霧島直樹と共に訪問し、圭吾の母・真紀子と共に圭吾に出迎えられる。真紀子から軽いうつの症状と書かれた1枚の診断書を見せられ、イジメの問題に気付かなかった学校側の責任を問い詰められるが、日向は不登校をしているのに笑顔で迎える圭吾に違和感を覚えたため、圭吾の部屋を見せるように真紀子に伝え許可をもらう。訪問後、日向は不登校の原因は学校だけでなく、真紀子にも原因があるのではと疑い始める。やがて、真紀子から圭吾が家出したと学校に連絡が入り、日向他教師たちが圭吾を捜し始め、夜中になって日向が高校の教室に戻ると、圭吾が自分の席に座っている。その後、日向と圭吾は体育館に行き、日向は圭吾に告白される。しかし、その翌日に彼は不可解な死を遂げた。...
The main character, Hinata Aizawa, is a school counselor at a high school, someone everyone could rely on. She listens to the students talk about their problems at school and at home. Hinata herself had experienced problems of her own, with her over-caring mother when she was growing up. One day, while Hinata is getting on with her daily work requirements, a male student who had been skipping school, comes to tell her that he loves her. However, the very next day, he dies in a mysterious death. An investigation into his death and his killer immediately begins. Eventually, all of the worries and problems which the victim had possessed becomes revealed. Various issues which surrounded his environment becomes more clear, such as the relationship with his mother and the troubles he had experienced with his girlfriend. As well, Hinata herself is unable to forget about what he had told her the day before his death. Despite all of this, she tries to uncover the reasons behind the student's death and faces up to various issues, by taking advantage of her positive attitude.
