With the ensemble contest behind them, the members of the Kitauji High School concert band now aim to win a gold medal at the national competition. For third-year club president Kumiko Oumae and her friends, it is their last chance before graduation. Filled with anticipation and anxiety, Kumiko worries if she can successfully lead the band. Amid her struggles, Kumiko encounters transfer student Mayu Kuroe. From her gentle demeanor to her talented euphonium skills, Mayu was a member of the Seira Girls' School concert band—a regular at nationals. While Mayu is friendly, Kumiko cannot help but have an indescribable feeling from their meeting. As new members arrive and plans are set in motion, the club, with an insatiable hunger for a gold medal, learns what it truly takes to propel themselves to reach the national level.

Hundreds of years ago, the borders between the worlds of humans and youkai temporarily overlapped, resulting in many residents of both crossing over to the other side. In the years since this event, the city of Sakurashin has become a central hub for all inter-dimensional affairs—a result of both the sacred Seven Pillars around the city serving as a beacon for the youkai, and the efforts of the Hiizumi Life Counseling Office in keeping the townsfolk happy. This office is composed of Hime Yarizakura, the young mayor of the city; satori Ao Nanami, who can read people's minds; half-youkai Kotoha Isone, who can summon anything by speaking a word; oni siblings, Kyousuke and Touka Kishi; and the office director Akina Hiizumi, who inherited his family's ability to force youkai back to their world. Besides volunteer and arbitration work, the Life Counseling Office also suppresses any Strikes: rare occurrences where humans are suddenly infused with youkai powers and go on a rampage. But the appearance of a sinister man signals trouble as Strikes become increasingly common, political rivals make their moves, and malicious individuals descend upon the city. As the self-appointed defenders of Sakurashin, it's up to the Life Counseling Office to protect the idyllic city they call home! [Written by MAL Rewrite]

The ordinary life of high school student Ayato Kamina is turned upside down when Tokyo is suddenly invaded by futuristic fighter jets. Amidst the chaos, he encounters a woman called Haruka Shitow who claims to be from a government organization called TERRA. She reveals that he has been living in a time bubble named "Tokyo Jupiter" that was put in place by the Mulians—humanoids from another dimension—in an attempt to isolate and take over Tokyo. TERRA has been trying to break through the barrier surrounding the city ever since. Unable to process the revelation, Ayato panics and flees. He runs into his classmate Reika Mishima who leads him to a place called "The Shrine of Xephon" where a large egg slumbers. She starts to sing and an unknown power awakens within Ayato, connecting him to a being called RahXephon that breaks out of the egg. Shortly after, Haruka finds him again and tries to make him join her cause of fighting against the Mulians. Caught between the crosshairs of the Mulians and TERRA, Ayato begins to question his purpose, navigating altered memories and ultimately his very identity in this chaotic new world. [Written by MAL Rewrite]