The film tells the story of three high school students who gather to help their friend's dream come true. Su-hyeon, the leader of the 8-member middle school band called A.D.H.D., lost five members to accident after they went to different high schools. His three close friends in high school join the band to help Su-hyeon fulfill his bucket-list, which is to perform on stage 20 times as A.D.H.D. However, having stopped playing for a long time, they had to ask their seniors to teach them perform. Could his bucket list be fulfilled?