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.

Butler Kim (Lee Jun-young), a man who replaces errands that start at 100 won per day, and Baek Dong-ju (Lee Hye-ri), a funeral director who grants the wishes of the dead, running an errand company.