It's time for phase three of Natsuki's Rainbow-Colored Youth Plan!

After a turbulent winter, the seasons turn once more, bringing Natsuki back to spring. His usual group has been split up into different homerooms, but that won't change the bonds they've built...right? At least his new classmates seem fun. On top of all that, Natsuki's hell-bent on taking the band seriously and must practice like crazy for the rapidly approaching music festival. Will Natsuki be able to successfully juggle friendship, extracurriculars, and romance?!