One day in the spring, the statue of a turtle in the corner of the playground suddenly "moved". What happened to the statue? Who is it, and why did they do it? The "deduction trio" of the fourth year class - Ama Tsujido, Roku Yuzuki, and Misuzu Kamiyama - are entrusted by their classmates with the task of deducing the truth about the turtle statue. They are commissioned by their classmates to take action! Can you take on the challenge of the great detective Tsujido Tenma? What is the truth of the matter? Go to the book to collect clues and start your exciting deduction!"