It is 1983, and Hinamizawa is under quarantine. A mysterious and deadly virus has been discovered within the small village, and its residents—such as teenager Keiichi Maebara and his friends Mion Sonozaki and Rena Ryuuguu—are left confused and frightened by the situation. As the villagers begin to search for a way to stop the affliction from spreading, some make drastic plans, which leaves Keiichi and his friends looking for a way to escape the village. But when tensions reach an all-time high, some of his group may not make it out unscathed as they fight for their lives against enemies both seen and unseen.

After losing a bet, Keiichi, Mion, Rena, Satoko and Rika parade around the town in costumes. When they come to a fork in the road, they decide to go to Yagouchi, a nearby abandoned village. Once there Keichii and Rena learn the mystery of a strange haunted quarry as they debate whether or not to check it out.

Movie adaptation of the Sekaiichi Hatsukoi: Yokozawa Takafumi no Baai BL light novel.

Two OVA episodes featuring additional stories. Episode 0: Ritsu and Takano used to date back in high school, but broke up due to a misunderstanding. This is that story. Episode 12.5: Hatori and Chiaki go to visit the latter's family. It's really awkward in many, many ways.