At Maigahara Music College Affiliate School Maigahara Senior High, there's a rumor circulating among students: "If you give an amazing performance at the school festival, you get special extra credit." Serina's grades are not very good, so she immediately believes the rumor and decides to form a band.

A group of friends have customized their microwave so that it can send text messages to the past. As they perform different experiments, an organization named SERN who has been doing their own research on time travel tracks them down and now the characters have to find a way to avoid being captured by them.