Keiichi's despair reaches its peak. After being captured and sedated, he wakes up restrained by Mion and Rena, and they attempt to inject him with a mysterious drug. Keiichi murders them before taking his own life by clawing his throat.

Satoko is absent from school for a few days. After discovering that the cause of her absence is Teppei, her abusive uncle, who left Hinamizawa after his wife was murdered on the night of Watanagishi, but recently has returned, Keiichi decides to intervene.

The events from Watanagashi-hen are retold from another point of view. Shion takes Mion's place in Hinamizawa and is lovestruck by Satoko's older brother, Satoshi, at their first meeting together. But after discovering about the trouble he spends to protect Satoko, Shion starts to loathe her.

Rena discover the true character of her father's girlfriend and grows a deep hatred for her.

The rest of the Yamainu concede defeat, but Takano is unwilling to surrender. After learning Nomura in Tokyo planned to use her as a scapegoat, she flees into the mountains and has a final confrontation with Rika's group. In the end, the Banken comes to arrest her, but Tomitake, pitying her and seeing how she had been infected with the Hinamizawa Syndrome, takes her into the the Irie Clinic for treatment. At the end, Rika and her friends Hanyū, Keiichi, Rena, Satoko, Mion, and Shion, attend the festival.