Hanako-kun's assistant Nene has suddenly been dragged inside a mirror. Through the looking glass, she meets the spirit of a young boy calling himself Mitsuba. They try to escape the mirrors together, but the threat of No. 3 of the Seven Mysteries, the Hell of Mirrors, draws nearer. Who is it that saves them just in the nick of time...!?
Through the workings of the School Mystery Clock Keepers, Kamome Academy's entire student body is covered in wrinkles!? To restore peace to the school, Hanako-kun teams up with a certain someone. Just when they thought the case was headed to its conclusion, the secret of Hanako-kun's assistant Nene is brought to light! What could it possibly be!?