卒業式を3日後に控えた欅台高校。生徒に人気の英語教師・水口里紗子が誘拐され、黒川良樹の元に、差出人不明の挑戦状が届く。
「誘拐の謎を解け。真相は君たちにしかわからない」
同じ挑戦状を受け取ったのは、サッカー部でスポーツ万能の荻生田隼平、校内ミスコングランプリの美少女・小松澪、そして黒川の幼なじみで学年一の秀才・高畑あやね。なぜこのメンバーが集められたのか不審に思う4人だったが、徐々に水口の別の顔が明らかになっていく。そしてまた、集められた生徒たちが問題を抱えていたことも・・・。
大藪春彦賞受賞の気鋭の作家・辻堂ゆめ原作。疾走しながら絆で結ばれてゆく若者たちの、青春ミステリー。
Keyakidai High School, three days before the graduation ceremony. Risako Mizuguchi, an English teacher popular with students, has been kidnapped, and Yoshiki Kurokawa receives a challenge letter from an unknown sender. "Solve the mystery of kidnapping. Only you can understand the truth." The same challenge was received by Junpei Ogyuda, who is a sports enthusiast in the soccer club, Mio Komatsu, a beautiful girl in the school's beauty pageant, and Kurokawa's childhood friend, one of the best talents, Ayane Takahata. The four were wondering why this member was gathered, but gradually another face of Mizuguchi became clear. And again, the students who were gathered had problems ... The youth mystery of young people who are sprinting and tied together with bonds.