Fumio Seki

He becomes math teacher in his third year of high school. He has the appearance of Eiichiro Funakoshi, an actor from "Tatsumi Shirou the Rogue Lawyer," the TV drama Wagatsuma Ai likes. He is time-slipper as well, and a quite skilled at that as he can time-slip at his own will. He reveals this to Hitoshi Aoshima in order to warn him that Wagatsuma Ai will die in ten years and that Hitoshi wouldn't be able to stop it.