山間の集落・雛見沢村へ越してきた前原圭一。村での賑やかな日々を大切に思っていたが…。 隠されていた連続怪死事件。不自然な態度の仲間達。そして、惨劇は繰り返す。 ――昭和58年の夏が、またやってくる。
Onidamashi-hen Part 1
A boy beats a girl to death with a baseball bat, lamenting that he loved patting her head and her smile, still trusting her. Another girl’s corpse is shown among them.
In June 1983, Keiichi Maebara wakes up, ready for his daily walk with Rena Ryuugu. It’s been 3 weeks since he moved to Hinamizawa. Rena greets Keiichi and walks with him for a bit, where they meet their other friend Mion Sonozaki.
At school they encounter a trap set in the classroom entrance. Keiichi sees that Satoko Houjou has almost gotten him with this one. Keiichi disarms the trap and triumphantly walks inside before tripping and almost planting face-first into an inkwell. Satoko gloats as Rika Furude pats Keiichi’s head. The group has a picnic later. Keiichi eats with his friends and wishes his everyday life could stay like this.
At the junkyard, Keiichi and Rena go for some treasure hunting. Rena searches for something in the junk and Keiichi relaxes only to be startled by a photographer appearing behind him. The man apologizes for scaring him and introduces himself as Tomitake. Tomitake asks what Rena’s doing down there, and Keiichi jokes that she’s looking for a dismembered corpse. Tomitake’s expression turns grim as he explains that it was a terrible incident, and they still haven’t found one of the arms. Keiichi wonders what he means and Rena returns. Tomitake leaves.
Rena exclaims that she found a Kenta-kun doll and wants to dig it up. Tomitake’s ominous message echoes in Keiichi’s mind, and he asks Rena if there were any incidents in the village. He’s heard about the dam project and wonders if any accidents happened, and Rena suddenly denies it. Rena explains that she was living somewhere else last year and doesn’t know much.
The next day, Mion inducts Keiichi as a new member of the games club. They decide to play a scavenger hunt game, the goal to find a marker hidden somewhere in the school. Satoko ultimately claims victory. As Satoko gloats, Rika presents her with a gift box. Satoko happily takes the box and accidentally presses a button on the side, getting belted with a boxing glove springing from the box. As the club laughs, Rena seems to be staring into space, distracted. She says she’s feeling tired and will go to the infirmary before heading home. Satoko escorts Rena there.
Keiichi and Mion walk home. Keiichi asks if anything happened at the construction site long ago, and Mion explains that the dam war happened. The villagers of Hinamizawa fought hard to get the project cancelled. Keiichi asks if anything violent happened, and Mion quickly replies that nothing like that occurred. Keiichi sees a strange look in Mion’s eyes, reminded of what Rena said earlier.
Keiichi goes to the junkyard and finds some magazines talking about a murder incident in the village years ago. People ganged up on a dam worker and beat him to death before hacking him to pieces. Rena appears behind Keiichi holding a hatchet.
Onidamashi-hen Part 2
Keiichi reads about the dismemberment incident and turns to see Rena behind him. They both scream and startle each other. Rena apologizes for scaring Keiichi and says she brought a hatchet to help get Kenta-kun out. Keiichi hides his magazines and says he came to the junkyard early to help. Keiichi takes the hatchet and hacks away at the boards keeping Kenta-kun in place, suddenly recalling memories of killing Rena and Mion with a bat. Keiichi pauses, and Rena asks what’s wrong. Keiichi says it’s nothing.
Kenta-kun is freed and Rena hugs it. Keiichi says to be careful or it’ll end up in pieces, and Rena glares at him with a strange look. Keiichi looks disturbed, and Rena pulls out a sheet and rope to wrap up Kenta-kun with. As they tie it up, Keiichi comments on Rena’s skill. They carry the doll home.
At the Watanagashi Festival, Rika greets the club wearing a shrine maiden outfit. The club has fun with stall games and meets Tomitake soon after that. Rike performs her ritual dance, and the club goes to do the cotton drifting. Rena tells Keiichi about Oyashiro-sama, Hinamizawa’s guardian deity.
The next day, Keiichi meets Detective Ooishi from the Okinomiya Police Department, who came to school to ask Keiichi some things. In private, Ooishi shows Keiichi a picture of Tomitake and another woman, asking when he saw them last. Keiichi says he last saw Tomitake at the festival, and Ooishi explains that the two were reported missing. Ooishi asks if Keiichi believes in curses and talks about the mysterious deaths and disappearances that have occurred every year. Ooishi gives Keiichi his phone number to call in case he learns anything relevant and warns that he shouldn’t let Mion or his friends know anything about this.
Keiichi and Rena walk home after school. Keiichi voices his concern that Rena and everyone else is hiding things from him, and Rena responds by asking the same to him. Rena asks if Keiichi’s hiding anything from her, a strange expression on her face as Keiichi grows concerned. Keiichi says he wouldn't do that but Rena says he’s lying; she knows he hid something at the junkyard and was talking to a strange man earlier. Keiichi says it’s none of her business and Rena suddenly grabs his head, professing that she’s always done the right thing and wonders how much someone has to struggle until they're happy. Rena sees misfortune as a cycle and says that relying on others doesn’t always work. She has to try hard by herself otherwise she won’t overcome things. Keiichi wonders what she’s trying to say here, and Rena goes back to normal when she says she also has things to hide. Rena walks ahead of Keiichi.
Onidamashi-hen Part 3
The next morning, Keiichi is still feeling disturbed by Rena’s sudden change. His mom tells him to stop by the clinic later. The previous night, Keiichi got a call from Ooishi and learned of Rena’s past in Ibaraki. He later learned from his dad that Rena visited his house and apparently listened to Keiichi on the phone from outside his room. Keiichi heads to school later that day and is made fun of by the club. Keiichi excuses himself to the infirmary since he still doesn’t feel good and Rika follows him. Rika asks if there’s anything on his mind making him feel uneasy, and Keiichi explains how creeped out he is by Rena. Rika yells that that’s a lie and pats his head, saying that whatever strange thing Rena said was one-time-only. Rika tells Keiichi to doubt himself and not Rena. Keiichi considers this and takes Rika’s words to heart.
Keiichi goes home and sees his parents are out for work. Rena appears at his doorstep bringing dinner wrapped in bentos. Keiichi gets suspicious but decides to heed Rika and trust Rena when she starts begging to be let inside. Keiichi recalls memories of Rena peeking through his door and then slamming her fingers with it while yelling at her to leave, along with more memories of doubting Rena and beating her to death as she holds her hands out to him.
Keiichi believes in Rena and invites her inside. Rena goes to the kitchen to prepare as Keiichi watches TV in the living room. He says he wants to apologize for angering Rena a few days ago and enters the kitchen, where Rena has laid out a hacksaw, string and other items. Rena scratches her neck and says she has to protect her dad as she stares at Keiichi. She walks towards Keiichi and says she needs to kill him and disappear. If she and Keiichi can become Oyashiro-sama’s curse this year, then her dad will get a peaceful life. Rena lunges at Keiichi with a knife and he pushes her down. They wrestle, with Rena managing to stab Keiichi. Keiichi in turn grabs a nearby clock and slams Rena with it. The two violently assault each other, ending with Keiichi shedding tears as a bloodied Rena lies on top of him.
Keiichi survives and ends up in the hospital. Mion says they couldn’t save Rena, but it’s fortunate they could save him. Mion cries and says that the day after the incident, Rika and Satoko were found dead at their home, stabbed in the necks. Mion leaves as the nurse arrives, who prepares a syringe and asks if Keiichi feels any itchiness in his neck. Keiichi scratches his neck and draws blood.
Rika reawakens in the Sea of Fragments, realizing that she’s died again and wonders what happened. She asks Hanyuu if she really has to repeat June 1983 all over again. Hanyuu apologizes and says she can’t explain anything in her current state. After escaping the previous time loop, Hanyuu distanced herself from the mortal world and entered a deep sleep so Rika could live a normal life; Hanyuu has no idea why the time loops are repeating again. Rika questions what this previous world is supposed to be then, because nothing like it has ever happened before. In this kind of world, Keiichi is supposed to succumb to paranoia and kill Mion and Rena, which is why she tried to address Keiichi’s concerns. Instead, tragedy happened anyway, and even Rika got killed. Rika doesn’t want to go through another hundred years and Hanyuu hugs her. Rika decides that she’s no longer ignorant of the truth and isn’t going to rely on lucky dice rolls like she used to. Rika believes she can overcome this fate so long as everybody is by her side.