School Mystery No. 1 s Clock Keeper of the future has gone out of control, turning Kamome Academy s entire student body into wrinkly old people! Hanako-kun, Nene, Kou, and Akane will have to work together to catch this agile trickster and keep the school from becoming a retirement home. But just when they seem to have Mirai cornered, one final prank goes horribly wrong, bringing Nene s secret out into the open...