In their previous lives, Jung Yunho, Kim Jaejoong, Park Yooqian and Kim Junsu were the four members of TVXQ, and they were the kings forever protected by their relatives. In the previous life, they made a promise that "we will go on forever", but... So these four loving children in God continue to reincarnate. In the present, they have turned into the most ordinary high school students, allowing them to rewrite the encounters in the previous life and rekindle the eternal promise of reincarnation together!