Thanks to the support of Sonozaki Oryou and other adults, most of Hinamizawa and parts of neighboring towns have come out in support of Keiichi’s efforts to save Satoko. The crowd is so large, Ooishi lumbers over to tell them they have to disperse. They don’t have a permit to demonstrate, and the CWS isn’t subject to mob rule.
The same laws meant to protect Satoko seem destined to torpedo Keiichi’s last gasp efforts, as any group dispersed now will surely be smaller next time around. Fortunately those in the highest positions of power have Keiichi & Co.’s backs, including Mion and Shion’s uncle, prefectural assemblyman, and another Sonozaki who’s a powerful lawyer.
The coup-de-grace that ends the CWS siege is Oryou herself, who pays a personal visit to the prefectural mayor along with her daughter to request the crowd’s demands be met. The mayor wouldn’t dream of going against Oryou, and so Keiichi and his friends are allowed inside. There, the cowardly director sends his assistant to confront Teppei. Ooishi gives him a ride to his house.
Later that evening, Keiichi gets a call from Satoko, who is safe and sound—if ominously framed throughout the call. She says learning about the extent to which Keiichi and others did for her sake, she stopped thinking it was best to keep enduring the pain, and cried out for help. When Teppei threatened her, he was arrested and detained. Satoko is now free from his clutches.
The next night is the Watanagashi festival, and the reunited group of friends decides to engage in a far more enjoyable battle than the one they just won: determine who can have the most fun! Festival food eating, target shooting and goldfish scooping ensue in a subsequent montage.
When Rika takes the stage for her sacred dance, Satoko pulls Keiichi aside. In a secluded spot, she asks if it’s okay if she calls him “nii-nii” from now on, making him officially her new big brother. He agrees, and she leads him to her house to give him an additional gift. It was at this point, with these two walking around the dark, that I started to worry about the curse.
Sure enough, the moment Keiichi switches on a lamp in Satoko’s house, Teppei comes at him from behind with a baseball bat. How the hell he escaped from jail isn’t explained, just that Keiichi suddenly snaps, wrests the bat from Teppei, and beats him to a bloody pulp. The uncle’s blood and brains splatter all over the room, Keiichi, and Satoko, and Keiichi then passes out from his own head wound.
The next morning, Keiichi is visited by Detective Kumagai, Ooishi’s colleague. He asks what happened last night at Satoko’s, but due to his head injury Keiichi simply can’t remember. Days pass, and no one comes to visit him except for Rena. He later learns there’s a reason for that: everyone else—including Satoko—are dead.
Rena tells him it’s a good thing he left the festival early, because Ooishi ran into the crowd and started firing his gun wildly, killing Mion, Shion, Rika and Satoko. I would guess that Satoko returned to the festival after running out of her house.
It’s an instance of Keiichi and everyone doing absolutely everything right on their way to a good ending, only for cruel fate to yank everyone back into not just a bad ending, but one of the worst possible. I honestly don’t know how Keiichi could have avoided disaster here. The curse appears to be more powerful than even a whole town united in its desire to protect a young girl whose parents supported the dam.