Keiichi tells Rena that he will be “taking a break from school” for a while. Rena hands him a community notice listing the disappearances. Keiichi wonders why she does not question him. He asks her if she knows that on that night he snuck into the Saiguden, but Rena already knows. She informs him that "Mi-chan" was "really mad," then slaps him in the face. "I don't think anyone punished you," Rena scolds, so she punishes him in place of everyone. Keiichi puts his hand to his sore cheek and apologizes.

Keiichi picks up the clip board of notices he dropped when she slapped him, and as he puts back the notices he sees one: “I’d like to share the best soy sauce I received from my relative Akita. Feel free to visit the Sonozaki family.” He startles with a flashback of Rika and Satoko's empty container and the "ring" left on the floor of the cabinet under the sink by the missing large soy bottle. He asks again, "Rena, you knew," and she nods her head. He then announces that he will go to Mion's home to apologize to her since he wants her to "end all of this."

A car arrives, and Oishi steps out and politely bows to them.

In the car, Ōishi rhetorically asks Keiichi if he feels "relieved" that he has finally told the truth. Kumagai Katsuya radios him to inform Ōishi that Mion informed the school that she will be absent. There is no activity at the Sonozaki house, and the "target" appears to be inside. Ōishi sighs and instructs him to maintain surveillance. When Keiichi asks about it, Oishi explains that neither his chief has not given permission for a probe, nor have they received permission to interrogate Mion, nor a warrant search her house. Rena angrily observes that the detective wants to use Keiichi to enter the Sonozaki house. If anything happened to him, Oishi could use that as an excuse to break into the home. Oishi sarcastically compliments her on being a "master detective." Rena storms out of the car, with Keiichi following behind her. Oishi smiles, then calls Kumagai.

Keichi and Rena walk to the Sonozaki residence. Keiichi is impresses by the size of the grounds. Rena rings the bell, and is greeted by a formally dressed Mion. "accepts" Keiichi's apology.]]At a table, Keiichi states he must "apologize." Sternly, Mion asks what he must apologize for. He confesses to and formally apologizes for entering the Saiguden. Mion smiles, looks to the side and replies that if he feels he did a bad thing, then she thinks that is sufficient. Rena protests that Keiichi is being sincere and Mion should respond seriously. Mion replies the she is being serious then asks if it looks like she is not being serious. Rena replies that is does. She then advises Keiichi to tell Mion everything since "that is what she wants." Keiichi asks Mion if she called Rika and Satoko over two days prior. Rena explains as she produces the Sonozaki flier that Rika should have come before dinnertime with a big bottle for some soy sauce. Mion stares at the flier. Rena continues: "And then you hid her away." She then explains that it should have ended for Mion then. Mion asks her what that is suppose to mean, and Rena replies that Mion did not expect Rika to tell Satoko she was coming over. Mion's expression changes to surprise as she listens to Rena explain how she deduced this. Mion stammers, then laughs hysterically. "I give up!" she screams, then she starts scratching at her hair. Rena continues to ask if the village headman "was also your," but Keiichi interrupts to add Tomitake Jirō and Takano Miyo.

Mion stops scratching her head, stands and steps back, then kneels formally to introduce herself to them as if it were the first time. She introduces herself as the heir to the Sonozaki family. She then states that she intends to speak honestly and openly to the best of her ability. She asks if Rena and Keiichi know that Hinamizawa was once called "Onigafuchi Village." When they nod that they do, Mion continues to explain that ancestors from Onigafuchi Village "were descendents with demon blood and proud sages." However, other villagers at the base of the mountain called them "demons" (鬼・oni) and attacked them. To protect themselves, they formed a faction. She reminds how residents rescued him against the gang that confronted him outside Angel Mort. For Hinamizawa to become a holy existence revered like Onigafuchi again, Mion proclaims is the wish of the inhabitants and the fate of the Sonozaki family: "heirs to the demon."

When Keiichi asks what "heir to the demon," means, Mion explains that "demon" is added to the name of the family's head. Keiichi understands that the "mi" (魅) of "Mion" is a character for "demon." Mion continues that she also has a "demon" engraved on her body. She stands to remove her top, but Rena gently responds that there is no need for her to reveal it. Mion thanks her, then walks to and opens the door to the garden. As the higurashi c ry, Mion begins to talk about he serial deaths over the past five years. She confesses to being directly involved in some of them while indirectly involved in others. She claims that the "other three families" committed some of the murders, but, ultimately, she feels she was in the center of them all.

Rena directly asks her if she killed Rika and Satoko. Mion merely responds that she will not make excuses since the demon dwells in her name, body, and heart. Rena reminds her that she spared one person: Keiichi. Mion slyly asks as she looks back at him why she did not kill "that person." She then asks if, perhaps, "Mion had reasons for not wanting to kill." Mion tells him, "I get the feeling that Mion liked you." Keiichi wonders that that means, but Rena "hushes" him. Mion turns back to the garden and rhetorically asks if Ōishi is waiting for her. When Rena responds "probably," Mion asks if there is a way out, but Rena replies that she does not think there is. Rena suggests that Mion turn herself in. She and Keiichi will go with her since they will never leave their best friend alone.

Mion scratches at her head again, then confesses that she cannot win against Rena. She stands and laughs. She asks Rena if before she turns herself in if she will leave her alone with Keiichi for 30 minutes. Outside walking along a stream, Mion blushes and asks to hold Keiichi’s arm. When he agrees, a leaf falls into the stream. She reveals that Shion liked him as well and that she is still alive. She then asks him to come with her to see all of her crimes. Keiichi replies that whatever he sees, "Sonozaki Mion is my best friend. And that will never change." Mion wonders how he and Rena can become so cool at such times.

She takes Keiichi to a set of heavy metal doors on the side of the mountain. She observes that "now is the time to turn back." When Keiichi announces that he will keep saying that Mion is his greatest best friend, Mion replies that she thinks she now knows what Mion liked him. She opens the doors to reveal a storeroom that contains what Keiichi believes are farm tools. Mion notes that he looked inside the Saiguden as she takes him down a set of stairs. She explains that the torture tools inside the Saiguden "were all made to enforce Onigafuchi Village's harsh precepts." Those who broke them were cruely killed as an example. She conducts him through doors at the foot of the stairs into another room which turns out to be the Sonozaki torture room. Mion explains that her family created it for the Watanagashi Festival, "even in present day." A wooden frame table, an iron maiden, and then a rack are shown. Mion sits on a modern bench which she explains are observation seats. She smiles and proudly announces that she "killed them all here." Keiichi asks where Shion is. Mion motions to a prison to the side. When he asks where Rika and Satoko are, Mion responds that since she did not want maggots to come, she threw them in a well.

As Mion looks darkly, Keiichi runs to Shion who is imprisoned in a cell. When Keiichi states that he is happy she is alive, Shion starts screaming at the sight of her sister's stare and scurries away from the bars. She begs her sister to kill her if she hates her so much.ed!]]Mion calmly picks up a rock and offers that "after I kill this guy" she will kill her slowly. Stunned, Keiichi watches Mion bring a rock down on his head as everything goes black.

He regains consciousness to discover that he has been strapped down on the wooden frame table by his hands and feet. As Shion screams from her prison, Mion laughs and sarcastically asks if she can hear since "It's about to begin!" Keiichi asks who she is. Surprised, she responds, "Sonozaki Mion." Keiichi denies this. Mion grabs a hammer and nails while condescendingly asking who she is suppose to be, to which he replies that she is a demon. She responds that she will tell him only one thing as she places a nail on his left fifth interphalangeal joint: "the demon" dwelled withing her for quite a while. As tears fall from her eyes, she explains that everything is his fault: if only he had given the doll to Mion. "If you hadn't made Mion cry, I wouldn't have woken up."

Mion explains her torture: she will hammer a nail into all of his finger joints. However, when she finds herself hesitating before she delivers the first blow. Keiichi offers that if it will calm the demon inside her, she may strike in exchange for two conditions. His first condition is for her promise to forgive Shion. Mion remarks that, even in his position, he is more worried about Shion than himself. He adds that his second condition is that the demon return Mion's body back to her. Looking disappointed, Mion withdraws the nail and wonders that he does not even think of begging for his life. With a smile, he adds that his third condition is that she does not kill him. She comes close to him and reminds him that he initially only said "two." He tries to laugh that off, but she reminds him that, as a demon, she probably will not keep any of her promises. She places her hand on his cheek and announces that she does not mind granting just his third wish: "To save Shion . . . That's impossible now." Further, to give her body back to Mion is also impossible now.

A loud banging from a distance is heard. Mion asks Keiichi if he hears it. She explains that since he did not come back, Rena probably called Ōishi. She brings her cheek to his and apologizes "for desecrating Mion." He replies that no matter what happens, the Mion within him will never change. She cries then withdraws from him. She tells him to forget about it. Even if he sees her after this day he must not come near her, since it will just be the demon that possessed her corpse. She produces a stun gun which she places against his neck. Everything goes blank for Keiichi.

Rena waits outside the open heavy doors as police ask for two stretchers. They carry out Keiichi and Shion. Keiichi narrates that Mion has not been caught yet as Ōishi watches police examine the Sonozaki torture room. Keiichi continues as Kumagai searches the depths that the bodies of the victims have also not been found. A television shows a news program discussing the crimes. Keiichi switches it off. His room is boxed up, and Rena sadly notes that he is moving away. As the higurashi c ry, Rena smiles and suggests that she will be lonely since she is the "only one left." Later that night, as he lays in bed, Keiichi hears stones striking his window and finds Mion outside.

He goes out to her and asks her if it is okay for her to wander around in Hinamizawa. Mion laughs innocently. He comes closer to her, and she lowers her head to admit that she wanted to talk to him one last time. She sweats, stares widely, and smiles as she claims, "I can't stay here anymore." Never one to read a room properly, Keiichi merely asks her if she is "okay." She ignores his question and continues to claim she has tried, but "I can't anymore." She lets out a maniacal laugh. Keiichi again asks her if she is "okay," and she responds by stabbing him in the stomach. As he watches his blood spread on his shirt, Mion continues to laugh and proclaim, "I did it in time!" and she managed to kill everyone she wanted to kill.

A dead Shion's face is covered by a blanked as Ōishi regrets her fate. Kumagai arranges the covering while Ōishi looks up from the pavement in front of a building to conclude she must have died instantly from her fall. Kumagai continues that they will investigate the case as a murder and accident as the scene reveals a ransacked room with an open window. Ōishi sighs in agreement.

"It can't be an accident," Keiichi tells Ōishi in his hospital room. He then asks if Mion has been found yet. Ōishi states that he came to update him on that. He claims that she was actually found. Further, the Sonozaki well was found which revealed, as Keiichi suggested, the bodies of all of the missing people. He then asks if he was really stabbed by Mion as he lights a cigarette. When Keiichi reminds him that the hospital is a non-smoking area, Ōishi dutifully opens the window. He continues to explain that Mion was not only found at the bottom of the well, she died the day they swarmed the compound. He then explains that an autopsy of Takano Miyo's body revealed she died 24 hours before she was found. Thus, when Keiichi snuck into the Saiguden on Watanagashi Festival night with her, she was already dead. He walks away musing that too many corpses walk around in this case.

A bloody hand reaches for his. Keiichi is surprised to see Mion come out from under his bed. "At that time, I granted you one wish," she explains. As blood streams down her face, she maniacly vows "but not anymore!" She produces a nail which she places, again, over his left fifth distal interphalangeal joint. As she laughs and raises a hammer, she brings it down hard and the screen turns red with a sickening sound of the violation of flesh.

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