Is Irodorimidori coming back?

At Maigahara Music College Affiliate School Maigahara Senior High (abbreviated as MaiMai) that gathers the most promising musical talents, there's a rumor circulating among students. "If you give an amazing performance at the school festival, you get special extra credit (or so they say)." Serina's grades are not very good, so she immediately believes the rumor and decides to form a band.