"Can't find the direction, go to the rainbow paradise, the love you said is touching the sorrow with happiness, the two of us will stay together until we are gray-haired, flying freely in the bright starlight, with you by my side..." Ajin was wearing headphones in the classroom, humming the song "Rainbow Paradise" by Liu Genghong softly, but he didn't know that Ahan was looking at him at this time, showing a sly smile, and he didn't know that it was because of this song that he and Ahan's life were closely connected...