In the year 2062, Earth finds itself fiercely battling Artemis—an AI which rebelled against humankind following a grand-scale workforce automation project failure years prior. In the hope of winning the war, a group of three highly skilled human warriors is assembled, known as the guardians of humanity. Empress, the last surviving guardian, wakes up alone in an empty research facility. Unable to recall anything from the past except a place called "Lighthouse No. 8," she begins to search for answers. It is not long before she discovers an impending threat from Artemis—and she is the sole person who can save the world from destruction.

After her crushing defeat of 21-0 at the National Junior Badminton Tournament, Nagisa Aragaki's love for her sport begins to distort. Unable to deal with the shame of loss, she starts to terrorize the members of her high school badminton club. Her grueling drills bring some to the verge of tears while others quit the club outright. With the team losing members and new prospects being too terrified to join, the future of the badminton club looks exceptionally grim. That is, until Kentarou Tachibana joins as the new head coach. Not only is he an Olympic-level player, but he also comes bearing a secret weapon: Ayano Hanesaki, the girl who defeated Nagisa six months ago. However, Ayano is not the rival Nagisa remembers, but a girl with conflicted feelings wanting to distance herself from badminton. With her future in sports now on the line, Nagisa must find a way to face her fears of inadequacy, heal her rival's troubled heart, and bring victory to Kitakomachi High School's badminton club. [Written by MAL Rewrite]

It is almost the end of the year, and Houkago Tea Time has been invited to participate in a live house on New Year's Eve! The iconic band members are Yui Hirasawa, the carefree guitarist who is enthusiastic to play music; Mio Akiyama, the shy bassist who gets embarrassed easily; Tsumugi Kotobuki, the gentle and sweet keyboardist who finds joy in normal activities; Ritsu Tainaka, the extroverted drummer who likes to tease Mio; and Azusa Nakano, the rhythm guitarist who is one year younger than the rest but slightly more mature. Performing in the set gives the girls the rare opportunity to meet various people from different bands, including the one that invited them, Love Crysis. Will Houkago Tea Time be able to delight their audiences successfully? [Written by MAL Rewrite]

Two OVA episodes are bundled as DVDs with each of volumes 6 and 7 of the manga. The first OVA is a prequel story written by the manga's author. Before the beginning of the main story, Rea and Chihiro have already met at a certain place: an outdoor hot-spring bath. The second OVA takes place after the series (effectively episode 14). The Furuya family finds a mysterious young girl hiding under the household temple.