Dali Desrong, who traveled to the world of the Lord of the mysteries, did not expect that he would return to the once warm home and the day of his eleventh birthday. When he thought that all the strange things were gone, he discovered a yellow-coated book in his birthday gift, and at the same time, a magical world slowly unfolded in front of him.……

At the end of summer, during a lunch break, I swapped bodies with a stranger from a parallel universe. My name is Zuo Yu, a senior high school student enjoying the typical high school life of going out five days and returning eleven, living a colorful youth amidst the stark contrast of exam papers. The person I swapped bodies with is Yukino Yukinoshita, a freshman high school student living a typical high school life, her presence absent from the vibrant high school world. Originally from parallel universes, leading parallel lives that would never intersect, our bodies were swapped, bringing us together.