Hotaru Ichijou's lifestyle completely changes when she leaves Tokyo and moves with her family to the isolated Asahigaoka village. Her new school has only five students including herself, all sharing a single classroom regardless of grade level. There are no convenience stores in the area, and it can take up to two hours for a bus to arrive. Nevertheless, Hotaru finds herself captivated by the countryside's charm thanks to her four unique schoolmates with whom she quickly forms a genuine bond. The most colorful of them is Renge Miyauchi, a first-grader who is often perceptive despite her age. However, no less intriguing are the three Koshigaya siblings: the quiet oldest brother Suguru, the petite older sister Komari, and the prankish youngest sister Natsumi. Having someone from the city join their cheerful little group enlivens the ordinary days in Asahigaoka. Not only does Hotaru bring firsthand knowledge from the alluring outside world, but her fresh outlook on life welcomes a blossom of change to their usual routine.

Third-year high school student Jirou Yakuin is in love with his childhood friend and classmate, Shiori Sakurazaka. Thus, he hopes to be paired with her for the marriage practical: their school's practice of randomly selecting boy-girl pairs to live as pretend married couples while monitoring and rating them on how close they have gotten. Meanwhile, the lively Akari Watanabe wants to be assigned to her crush, the popular and good-looking Minami Tenjin. Much to their dismay, Jirou and Akari find out that not only have they been paired together, but so have Shiori and Minami! Determined to be with their crushes, Jirou and Akari strive to earn as many points as possible, as the top 10 pairs earn the right to switch their partners—so long as both couples agree.

After a fatal encounter with a truck, Takafumi Takaoka's uncle, Yousuke Ojisan Shibazaki, lies comatose for 17 years. When he finally regains consciousness, Ojisan begins to ramble in a foreign tongue and reveals that he had been transported to a magical world called Gran Bahamal. Takafumi dismisses his uncle's claims as nonsense until an incantation makes a cup of water hover in the air. In a flash of brilliance, the pair creates a YouTube channel to showcase Ojisan's magical abilities. The responsibility now falls on Takafumi's shoulders to acquaint Ojisan with everything that has transpired during his absence, including getting him up to speed with the internet, new technology, and surprisingly, the outcome of the '90s console war—the result of which was especially distressing for a hardcore SEGA fan. With Ojisan's wisdom from his other world experiences, they grow their YouTube channel and tackle online comments and trolls. The journey of this uncle-nephew duo promises to be anything but conventional.

Fuutarou Uesugi's efforts as the Nakano quintuplets' private tutor are finally paying off. The academic performances of the five sisters are steadily improving, and they are each closer than ever to achieving their respective dreams. However, it appears that Fuutarou has become more than a teacher for the girls, who urge him to sort out his feelings. The undecided young man promises to make a decision by the end of the school festival. However, Fuutarou's task will not be easy, as the Nakano sisters pull out all the stops to win his heart before it is too late.