Rika Furude and Satoko Houjou are best friends who have lived in the small village of Hinamizawa for their entire lives. Alongside their other friends, they spend every day together, and every moment is filled with fun and laughter. However, as Rika and Satoko begin to grow older, a life-changing opportunity presents itself to both of them. Rika is determined to follow her dreams and wants Satoko by her side. Although Satoko is hesitant, she decides to walk this path with Rika. However, the realization of her dream forms a rift between them. This leaves the girls living in completely different worlds, with Rika enjoying her new life and making new friends while Satoko grows more and more isolated. Longing to return to the nostalgic days in Hinamizawa, Satoko despairs and wishes things could be changed. Just when she is at wits' end, an encounter with a supernatural entity changes Satoko's perception and imparts new revelations about her best friend Rika. This begins her journey to get the future she desires—by any means necessary.

Haruka Nanase and Makoto Tachibana have started middle school and must adjust to the changes that come along with growing up. While Makoto fits in with his classmates and remains positive about swimming, Haruka struggles to befriend others or join his school's swim club, as his previous issues with swimming trouble him. Distancing himself from his lively classmates and the swimming club, he has difficulty deciding which club to join instead. The rest of his classmates, including Makoto, are also hesitant as to which clubs to participate in. After an argument leads them to join the swimming club anyway, the boys strive to hone their skills, harmonize their swimming styles, and refine their conflicting feelings toward swimming and each other. As determination and talent run high, Haruka and Makoto—along with their classmates—discover themselves and improve their talents during their starting days.

1. Batsukoishi-hen 2. Ayakashisenshi-hen 3. Musubienishi-hen 4. Yumeutsushi-hen

As a punishment for losing an intense poker game, Keiichi Maebara, Rena Ryuuguu, Mion Sonozaki, Satoko Houjou, and Rika Furude must walk around town dressed in costumes. Wanting to avoid being seen by more people, Keiichi convinces the group to visit Yagouchi—a deserted neighboring village. Mion's mention of a nearby abandoned quarry spikes the attention of Rena and Keiichi. Still, as she tells them more about the mysterious incidents surrounding the place, they debate whether it would be wise to explore it.