Yuuya Tenjou has been bullied all his life. Then he discovers a door to another world. Powerful weapons. Vicious monsters. It all seems like a fantasy game! And when he returns to his world, he realizes that his leveling up comes with him.

When Yuuya reunites with the girl he saved back at the convenience store, she invites him to attend the prestigious Ousei Academy. Yuuya isn’t sure that he’s worthy of attending a school full of geniuses, but he’s persuaded to try it for just one day.

Yuya responds to Princess Lexia's marriage proposal and receives an invitation to an audience at the royal palace. At the same time, he returned to the Ôsei Academy.