Yuta and Rikka may finally be together, but things haven’t settled down just yet! The arrival of Yuta’s childhood friend, the extra-eccentric Satone Shichimiya, is about to take this couple’s relationship from delusional to downright crazy. Not only is Satone a full-time chunibyo sufferer herself, but now she’s claiming to be Yuta’s one and only soul mate. If Yuta and Rikka want to make their relationship a reality, they’ll have to break through Satone’s fantasies first!

Spring in the first year of high school. Kumiko, a member of the brass band in junior high school, visits the high school brass band club with classmates Hazuki and Sapphire. There, she comes across Reina, her former classmate from junior high. Hazuki and Sapphire decide to join the club, but Kumiko can’t make up her mind. She recollects her experience with Reina at a competition in junior high school.