Middle-aged salaryman Hiroshi Nakahara accidentally takes a train ride back to his old hometown to visit his mother’s grave. Then for reasons he can’t explain, Hiroshi is transported back in time, and discovers that he’s an 8th grader again, but with all of his adult memories intact.

Can he, or should he try to change the decisions he made before? But more importantly, can he find his way back to the present day, or is he stuck in the past?