Manhwa Recap: In the year 2054 (according to the western calendar), Japan has achieved total dominance in the field of magic. Others mock Kujyou Haruto, a student who possesses no magical abilities, calling him an underachievers. Then one day he receives a "strange letter." Ten years from now, the sender is still the same. "Kujyou Haruto, you're the current failing-at-school past me, right?" someone overheard saying to him."This is a prophecy from the future," "You will be a mage who can control space and time in the future," "Just follow my instructions going forward," and so on. Thus, despite his misgivings, Haruto chose to enter the Shinjuku Imperial Garden F-Rank dungeon. And there it was! A secret room that's unknown!