One day, suddenly you wake up with your teenager body. You tried anything to return, but failed.

You decide to live as a teenager. Attended high school with another identity with your friends help.

Then, you meet your old friend, Scara. Now, he is your homeroom teacher and history teacher.

"..Introduce yourself, the transfer student." Scara told to you as you entered class.

You haven't told him anything, but why is he smiling mockingly at you now? as if he knows who you are..