Tsukiotoshi-hen

Tsukiotoshi-hen (憑落し編) is the second arc in. It is primarily told from the perspective of Keiichi Maebara as he attempts to save Satoko Houjou from her abusive uncle. It serves as an alternate version of.

Plot
Keiichi Maebara expresses her concern for Satoko Houjou, who has recently stopped coming to school. Rena Ryuuguu deduces that Satoko's abusive uncle, Teppei Houjou, has returned to Hinamizawa and is responsible for her absence. This leads to a fight between Shion and Mion Sonozaki over the unwillingness of the Sonozaki family to help Satoko. Keiichi and Shion attempt to enlist Rumiko Chie in their effort to help Satoko, however she is insistent that the pair should wait before taking action. Ignoring her advice, Keiichi and Shion break into Satoko's house and interrupt a mahjong game between Teppei and his friends. Keiichi is briefly attacked before Kyousuke Irie arrives and defuses the situation. Satoko insists that there is no abuse to worry about and asks the group to leave.

Keiichi is frustrated by his inability to help Satoko. Rena guides him to the dam construction site and brings him to her secret hideout. While inside, Rena confesses her plan to murder Teppei. The next day, Keiichi convinces Shion to join him in visiting Rena at the secret hideout. Keiichi declares that he will be the one to kill Teppei, with Shion and Rena eager to help him. The three form a plan and carry out the murder on the night of the Watanagashi Festival. However, Satoko goes looking for her uncle and witnesses the trio burying Teppei. Shion knocks her out with a stun gun and brings her to a secluded location while Keiichi and Rena go to the Watanagashi Festival.

Two days later, the trio meet at the Okinomiya library. Shion reveals how the police investigation into Teppei's disappearance has progressed as well as the fact that Jirou Tomitake and Miyo Takano had died on the night of the Watanagashi Festival. This conversation is interrupted by Kuraudo Ooishi, who proceeds to interrogate the trio regarding their whereabouts during the festival. Shion quickly leaves.

Time passes, however Satoko never returns to school and Shion refuses to reveal her location. Keiichi, Rena, and Rika Furude go to Shion's apartment in Shishibone City and are intercepted by Ooishi. Ooishi informs them that Shion hasn't returned home since the day of the festival. Worried for Satoko's safety, Keiichi, Rena, and Rika break into Satoko's house and find Shion and Satoko's corpses on a futon.

The next day, Keiichi receives a call from someone claiming to be Shion. Keiichi tricks the caller into meeting him and Rena at the dam construction site. The caller, Mion, confesses that she was initially impersonating Shion because she was jealous of Keiichi's relationship with Rena and Shion. After the festival, she continued impersonating Shion in an attempt to create an alibi for her. Keiichi and Rena come to the conclusion that Mion is lying to them and had killed Shion and Satoko herself under orders from the Sonozaki family. Furious, the two attack and murder Mion.

Keiichi and Rena load Mion's body into a wheelbarrow and pull it to Satoko's house, adding Mion's body to Shion and Satoko's. Rena starts a fire using junk mail from the mailbox and vegetable oil. As the house burns down, Rena stabs Keiichi in the stomach with a knife, believing that he was planning on killing her first.

Rena leaves the house and goes to the Furude Shrine to find and kill Rika. When she arrives, however, she learns that Rika has already been killed. Furthermore, Rena realizes that she is being monitored by the Okinomiya police department. Rena attempts to escape and loses consciousness in the forest. When she comes to, she finds herself near the school, surrounded by armed soldiers. She escapes again but is shot in the process. She comes across a dying police officer who warns her that a toxic gas has leaked from the Onigafuchi swamp and tells her to leave Hinamizawa. Rena returns to the dam construction site and takes refuge in her secret hideout. Inside, Rena finds a notebook and resolves to tell someone important about it. When she leaves her hideout, she is immediately shot and killed.

Villagers

 * Keiichi Maebara
 * Shion Sonozaki
 * Mion Sonozaki
 * Rena Ryuuguu
 * Rika Furude
 * Satoko Houjou
 * Teppei Houjou
 * Rumiko Chie
 * Yoshiroh Sonozaki

Outsiders

 * Kuraudo Ooishi
 * Tatsuyoshi Kasai
 * Katsuya Kumagai

Mentioned

 * Rina Mamiya
 * Jirou Tomitake
 * Miyo Takano
 * Satoshi Houjou

Deaths and Disappearances
All deaths and disappearances are listed only as they are told in  and apply only for the individual arc, not the overall series.

Deaths

 * Jirou Tomitake, died of blood loss after clawing out his own throat June 19, 1983 on the night of the Watanagashi.
 * Miyo Takano, killed and burned in an oil drum in the Gifu Mountains June 19, 1983 on the night of the Watanagashi.
 * Teppei Houjou, beaten to death with a baseball bat by Keiichi Maebara June 19, 1983.
 * Satoko Houjou, died of blood loss after clawing out her own throat June 1983.
 * Shion Sonozaki, stabbed to death June 1983.
 * Mion Sonozaki, hacked to death by Keiichi Maebara and Rena Ryuuguu June 23, 1983.
 * Keiichi Maebara, stabbed in the stomach by Rena Ryuuguu June 23, 1983.
 * Rika Furude, found disemboweled June 23, 1983 in front of the Furude Shrine.
 * A police officer, shot and killed by the Mountain Hounds June 23, 1983
 * Rena Ryuuguu, shot and killed by the Mountain Hounds June 23, 1983.
 * Everyone in Hinamizawa not listed otherwise, died June 23, 1983 of gas poisoning during the Great Hinamizawa Disaster.
 * Some people who used to live in Hinamizawa, started showing erratic behavior right after the Great Hinamizawa Disaster. Some died mysteriously in hospitals, while others started dying in other strange ways.

Disappearances

 * Satoshi Houjou, disappeared June 1982, one year before the story.

Trivia

 * Completing this arc unlocks the second ending in Taraimawashi-hen.