Hanju is your ordinary university student… except for the fact that she’s also the up-and-coming Metube cover artist, PLII. When popular boy group member Levi takes notice of PLII and requests to collaborate, Hanju will do anything to hide her secret identity. But as the two grow closer working on a class project, Hanju’s cover begins to unravel. Will Levi discover her secret?

A CODA (child of deaf adult) student born with a gift for music crash lands at an unfamiliar place after time traveling through a suspicious music shop. There, he forms the band Watermelon Sugar with other mysterious youths.

A boy falls to his death at school, but Ok Chan-mi does not believe that her twin brother, Park Won-seok, committed suicide. Chan-mi transfers to her brother's school, Yongtan High, and meets Ji Soo-heon, who witnessed her brother's death. A "hero," who avenges bullied students, appears at Yongtan High. Chan-mi speculates that it may be connected to her brother and starts looking for this hero.