Voiced by: Fumiko Orikasa (JP), Sam Carr (EN, Bang Zoom), Macy Johnson (EN, Funimation)
Portrayed by: Hitomi Miwa (film)
The female teacher of Keiichi's class, who is a parody character of Tsukihime's Ciel-senpai (permission for her usage was given by Type-Moon). The voice actress for her character in the anime series is the same as the voice actress for Ciel from the Tsukihime anime. Going along with the parody, her favorite food is curry rice, just like Ciel.
- Berserk Button: Don't you dare insult curry in front of her. It won't be pretty. Sometimes she can hear an insult even when she's not in the room!
- Curtains Match the Window: She has blue hair and blue eyes.
- Expy: She's clearly based on Ciel from Tsukihime, and Type-Moon even granted permission to 07th Expansion to do so. She seems to be more specifically based on Ciel-sensei, the version of Ciel that appears in Tsukihime's "Teach me, Ciel-sensei!" segments; she even wears the same pendant.note If that wasn't enough, in Higurashi Daybreak, many of Rumiko's moves are direct references to some of Ciel's moves from Melty Blood. In the Expansion Pack, one of Rumiko's alternate outfits is Ciel's nun outfit and, if the player uses this costume, she will talk very much like her Tsukihime counterpart.
- Hot Teacher: Parodied in Kira with Keiichi "sketching" her as punishment game in the Soul Brother's delusion.
- My Nayme Is: Her name is oddly spelled "Lumiko Cie" in the French version, most likely to make her Punny Name more obvious.
- Punny Name: Her name in Japanese order is Chie Rumiko. If you combine "Chie" and "Ru", you get "Chieru", which sounds very similar to the Japanese pronuncation of Ciel's name.
- Reasonable Authority Figure: Unfortunately, there's generally little she can do.
- Schoolmarm: She's the only teacher at the school the main characters attend, which isn't surprising since Hinamizawa is a rural village and the school is a one-room schoolhouse with a single class of children of different ages. Keiichi is impressed that she manages to teach a class full of students from different grades. Higher grade students are also expected to teach to lower grade ones during free study periods, effectively raising the number of teachers.
- Serious Business: Curry, both cooking it and respecting its history. Rena says she's a tyrant when it comes to curry.
- Stern Teacher: In the visual novel, Rena states that Rumiko would not hesitate to discipline her students who had crossed the line with harsh methods, such as hitting them with a wooden ruler. This is never brought up in the anime, where she's generally nice to her students.
- Trademark Favorite Food: Curry, which is yet another indication that she's an expy of Ciel.
- You Gotta Have Blue Hair: Her hair is dark blue, which is another trait she has in common with Ciel.
Voiced by: Fumihiko Tachiki (JP), Steve Kramer (EN)
An employee of the Sonozakis and Shion's personal bodyguard, who looks like a secret agent.
- Badass Beard: His goatee beard is one of the many things that make clear he's no one to be messed with.
- Badass in a Nice Suit: He's always dressed in a black suit as expected from a bodyguard and retired Yakuza.
- Cool Shades: He wears sunglasses as part of his stereotypical tough bodyguard look.
- Hired Help as Family: He works as Shion's personal bodyguard, yet he's more like real family to her than any Sonozaki except for maybe Mion and Akane. When Kasai tells her he can't protect her if she's going to be punished for sneaking inside the Saiguden, Shion feels the most betrayed because she had hoped Kasai would side with her even if no one in the Sonozakis did.
- Red Baron: "Shotgun Tatsu". Do not mess with this guy!
- Romantic Runner-Up: According to Shion, her father, Kasai and Akane had a Love Triangle in their youth. Kasai lost but stayed close to Akane as right-hand man. It didn't end so badly for him at all since he does get to watch over Shion.
- Shotguns Are Just Better: He wields a shotgun during the assault on the Irie clinic in Matsuribayashi. A single slug from it tears a massive hole through the door and the table the guards were using as cover, scaring them shitless. A second shot gets them all to surrender except for one.
- Retired Badass: He was a more active member of the local Yakuza in the past, but has settled down to become Shion's caretaker.
- Sunglasses at Night: He is always seen wearing sunglasses.
Voiced by: Shumpei Otani (JP), Kyle Hebert (EN, Bang Zoom), Anthony DiMascio (EN, Funimation)
A police officer in Okinomiya who assists Ooishi in his investigation.
- Straight Man: He plays the calm By-the-Book Cop to Ooishi's Bunny-Ears Lawyer. Often times being the level-headed Foil to Ooishi's boistrous antics.
- The Watson: Ooishi often explains what's on his mind to Kumagai in the process letting the audience know what the police know. It's especially prominent in the TIPS where no protagonists are present for Ooshi to play off of.
Voiced by: Katsuhisa Hoki (JP), Steve Kramer (EN, Bang Zoom), Bryan Massey (EN, Funimation)
Portrayed by: Riki Takeuchi (film), Tomohiro Waki (drama series)
Satoko and Satoshi's uncle/foster father. He and his wife were forced to take care of Satoko and Satoshi after the death of their parents, but they abused them. He left Hinamizawa after Tamae's death, and currently lives in Okinomiya.
- Abusive Parents: He's Satoko's uncle, but ends up as her direct guardian in some arcs, making him a parental figure. Not only does he treat Satoko like crap and hits her, one of the TIPS flat-out states that if she had been a few years older, he would have had no qualms about abusing her sexually too. It doesn't end well for him.
- Ain't Too Proud to Beg: Another sign of how drastically different he's become in Sotsu is that he goes to Ooishi to kowtow and beg him to help Satoko out when it seems like the town's against his niece. Ooishi is flat-out stunned by his behavior, though implores the request.
- Ascended Extra: In Gou and Sotsu, he undergoes some significant Character Development and is a major supporting character, which is a drastic change for a previously flat bit character that practically only existed to inspire audience hatred.
- Asshole Victim: He gets by Keiichi and Rena in Tatarigoroshi and Tsumihoroboshi respectively for tormenting their loved ones, but in Miotsukushi-hen, Takano injects him with H173 to induce the final stages of Hinamizawa Syndrome. He'd been abusing Satoko earlier in the arc, so no tears are shed.
- Child Hater: Taken to truly repulsive levels in Tatagoroshi and Minagoroshi-hen.
- Clawing at Own Throat: His fate in Miotsukushi-hen is being selected by Takano as Tomitake's replacement the night of the Watanagashi Festival. She injects him with H173 and he dies by clawing his own throat out.
- Dying Alone: Defied. In Gou episode 23 where he starts remembering past loops, Teppei realizes that his jerkass and abusive behavior is pushing everyone, including Satoko, away to the point that there's no one who will care if he dies alone. He resolves to be a better person and take better care of himself from then on to avoid this fate, or at least not to be an unnecessary burden on everyone around him.
- Evil Is Petty: While he's depicted as a despicable person all through, the Gou season exaggerates his pettiness at the beginning of episode 12 when he vandalizes a roadside shrine and pees on the torii shrine gates off-screen. However In Sotsu, this is subverted as it turns out that Teppei has already turned over a new leaf so that he can treat Satoko better. It was actually Ooishi who was responsible for it after Satoko injected him with the H173 vaccine so he can frame Teppei and see him in a bad light.
- Evil Uncle: He has a history of beating his niece and nephew Satoko and Satoshi. He's not even their real uncle. His older brother was their stepfather. Gets out of this by Gou episode 23, buying Satoko snacks and protecting her from the Motorcycle Gang, wanting to be a better uncle to Satoko even if she can't forgive him.
- Gaslighting: A major victim of this at the hands of Satoko in Sotsu, ironically enough. She claims that the village and her friends hate and bully her, and make her life a living Hell, but refuses to let him get any sort of "revenge" for this.
- Hated by All: Everyone in Hinamizawa either fears or despises him. This played for drama in certain instances where his abysmal social standing makes it easier for people to believe he's behind a crime even when he isn't.
- Hate Sink: He clearly was meant as someone who the audience wants to suffer, and does. Ironically, subverted in Gou and Sotsu
- HeelFace Door-Slam: A Jerkass Realization in Gou episode 23 from remembering past loops makes Teppei resolve to try to be a better person and be the uncle Satoko needs, buying her snacks and protecting her from a Motorcycle Gang. But it is too bad Satoko is still suffering from his abuse too much to be able to forgive him.
- Heel Realization: Subverted. In Gou episode 23, Teppei begins remembering his past loops. The horror of dying alone so many times coupled with reliving the consequences of his abusive and brutish behavior over and over in an isolated and miserable life makes him regret all his prior actions, deciding to change for the better by losing the Hair-Trigger Temper and trying to be kinder towards Satoko, which continues into Sotsu. Too bad that Satoko is taking advantage of Teppei's attempts to change and manipulates him until he lets his guard down and kills him.
- Irony: In Sotsu, Teppei becomes a much nicer person around the same exact time Satoko is becoming a much more selfish person who's doing worse than he ever did.
- I Was Just Passing Through: In Gou, Teppei saves Satoko from some thugs and when Ooishi questions him, Teppei tries to pretend he only felt like picking a fight because even he knows he isn't the type of man he would go out of his way to protect the very niece who he abused in the past. Satoko and other witnesses do attest that he was defending her, getting him out of trouble.
- Jerkass: Even in episodes where he isn't doing anything morally reprehensible, he's still an asshole. Subverted in Gou episode 23, where the Teppei of that episode's world decides to change for the better after a series of bad dreams involving his deaths in past loops.
- Jerk with a Heart of Jerk: Played With. Even in Gou episode 23 where he has a Heel Realization and tries to change his ways, while keeping himself to his word of no longer abusing Satoko, Teppei still stalks her the day after he'd met up with her again and tries to worm his way back into her life explicitly because there would be benefit for him in doing so, and he seems to regret the negative impact his poor life choices have had on himself first and foremost rather than being remorseful about all the people he'd hurt, his young niece and nephew included. In the reality of "Curse Deceiving", it's heavily suggested that Satoko did choose to let him back into her life and was only lying about his continued abuse to her friends, and by the end of that arc he's driven to attempting to murder Keichi when Satoko lets the latter into the Houjou home, suggesting that despite his best efforts to change, he still ends up slipping back into his old ways when pushed far enough. That said, Sotsu shows that his 180 degree flip on Satoko is genuine, in addition shown to being genuinely friendly with people with her presence, Teppei practically only does things with her if she allows it, and waits for her to approach him, not the other way around. At one point, he gets so upset about the alleged abuse she's suffering from the village, he's actually driven to tears because he's unable to help her. It's largely due to Satoko's manipulation that his violence and bad behavior come back. However, in the end, his violent side never makes a reappearance, Satoko kills him before an such thing happens.
- Karmic Death:
- In Tatarigoshi, Exorcism, and Tsumihoroboshi, he's killed by one or several members of the club either to free Satoko from his abuse or to get back at him for him and Rina extorting money from Rena's father.
- In Sotsu. On one hand, he's killed by his past abuse victim, Satoko. On the other hand, by the time she actually does do this, Teppei is actively trying to be better.
- Knight of Cerebus: His presence always signifies things getting unpleasant. Lampshaded by Rika in the Massacre Chapter: in any world where Satoko's uncle returns to Hinamizawa, Rika feels she might as well give up at trying to fight against any circumstances.
- A Lighter Shade of Black: Astonishingly in Sotsu. While Teppei was a huge asshole with zero redeeming qualities, he has a realization that his bad behavior is gonna have him dying brutally and without anyone caring about him. As such, he slowly attempts become something better, while Satoko, one of his former victims and clearly traumatized by his abuse, has gone through some MAJOR levels in jerkassery and is responsible for murder (both directly and indirectly), torture, gaslighting, and emotional and psychological abuse.
- Loan Shark: One of his activities is threatening people into signing loans with him, with the help of Rina.
- Lonely Together: The reason why he suddenly tries to be nice to Satoko in Gou is because he realized that they're each other's only family in the world. Satoko calls him out on how he's only looking for someone who feels as lonely as him so they'll take care of him for free and he doesn't deny it, but still wishes that he and Satoko can at least be on speaking terms.
- Oh, Crap!: That's how most normal people react to putting the light on and seeing what was a cute teenage girl 2 seconds ago, brandishing an axe ready to cleave your head in two. Or seeing a furious teenage boy charging at you with a baseball bat while screaming like a banshee. He doesn't have the time to say it out loud in either scenario though.
- OOC Is Serious Business: After years of being the biggest asshole in Higurashi with even Rika considering his return the point of no return for any given loop, Teppei does a complete 180 in Gou episode 23. Remembering his past loops convinces him to change his ways, losing his Hair-Trigger Temper, taking better care of himself and going so far as to buy snacks for Satoko with his pachinko winnings and beating up the Motorcycle Gang attacking her. Both himself and Ooishi even lampshade it, Teppei saying unreservedly that this change is outright unnatural for someone like him.
- Outlaw Couple: According to Kasai, he is a pimp and uses his lover Rina to swindle men out of their money.
- Pay Evil unto Evil: Whenever he's killed, it's because someone found his actions so horrible, they thought he no longer had the right to live.
- Pet the Dog: While one could argue that him giving Satoko his snacks and later saving her from the biker thugs in Gou episode 23 was still largely self-motivated, as he'd wanted Satoko to let him back into her life so that he could live Lonely Together with her in Hinamizawa and be better taken care of, he did show himself capable of doing something decent for Satoko at the end - respecting her wishes for him to back off from her, putting space between the two of them when it was clear she was too traumatized by his past abuse to even entertain forgiving him to the point of being on speaking terms with him again, let alone letting him live with her.
- Rejected Apology: In Gou episode 23, Teppei decides to change himself for the better and mend his frayed relationship with Satoko. Even if Satoko won't live with him again (knowing his past abuses are already unforgivable), he at least wants to be on speaking terms with her again. However, Satoko is still suffering from the after-effects of his abuse and pushes him away.
- Ripple Effect-Proof Memory: In Gou, Teppei suddenly begins remembering his past loops which he explains away as bad dreams, including one where he is killed by a trio of the Sonozaki's yakuza gang. The terror of the previous loops combined with a Heel Realization convinces him to begin righting his past wrongs.
- They Killed Kenny: Dies quite a lot, mostly to his own evil acts biting him in the ass.
- Took a Level in Kindness: In Gou, after having recurring "nightmares" (which are most likely him remembering the alternate timelines where he died), he undergoes a Heel Realization, and decides to turn over a new leaf, even going out of his way to be kind to Satoko. In Sotsu, he becomes very protective of Satoko, though he remains respectful of whatever she asks of him and does not ask for anything in return.
- Unwitting Instigator of Doom: Rika considers his return to Hinamizawa to be one of the worst possible omens for a new timeline. In timelines where he comes back to the village, his presence - in particular his destabilizing influence on Satoko - invariably dooms any and all efforts at making things better. It gets to the point that when he appears in Minagoroshi, Rika considers simply killing herself to save herself some heartache, as she is convinced that despite the fact that the timeline has had some excellent turns of luck thus far, his mere presence in the village has doomed it beyond any hope of recovery.
- Unwitting Pawn: Once Satoko realizes her looping is making Teppei more remorseful, she decides to use this opportunity to exploit his newfound kindness in any way that can benefit her. In Tatariakashi-hen, she actively asks Teppei to come live with her in their old house to reenact the loops where he returns to Hinamizawa to fool Rika further, and to make sure he'd act like his old, belligerent self to others as part of this front, she tells him the village is actively bullying her for being part of the Houjou family.
- Vigilante Execution: Vigilante action (for NASTY child abuse and badger games) is the common motive in his many deaths throughout the arcs.
- Would Hurt a Child: As long as he has someone to hit, he's not picky about the age. He also kills Rika in an unseen world.
Voiced by: Kyoko Hikami (JP - drama CD), Misa Watanabe (JP - anime), Jean Smart (EN, Bang Zoom), Morgan Garrett (EN, Funimation)
Portrayed by: Aya Sugimoto (film), Rei Yoshii (drama series)
A woman who appears in Rena's life in Tsumihoroboshi-hen. She is the lover of Teppei Houjou.
- Alas, Poor Villain: In Sotsu, she has a change of heart about what she is doing because she used to be a single child just like Rena, and even tries to tell Rena that she should convince her father to break it off with her. Which makes Rena murdering her a lot less warranted.
- Asshole Victim: She's killed by Takano and the Yamainu after sneaking into the Irie clinic in Miotsukushi.
- Bare Your Midriff: She wears a tube top that exposes her belly. Her Sotsu outfit exposes several more feet of midriff than before.
- Bitch in Sheep's Clothing: When Rina confronts Rena about the fact that she doesn't like her, and Rina puts on a pretty convincing act about how she genuinely loves Rena's father. Rena falls for it and starts to reconsider her view on Rina before she overheard her and Teppei badmouthing her father.
- Blatant Lies: "I'm pregnant. And since I'm a Christian, I can't have an abortion."
- Bludgeoned to Death: In Tsumihoroboshi-hen, Rena kills her by beating her skull open with an iron pipe.
- Consummate Liar: For a moment, she managed to fool Rena into thinking she really loved her father. That's until Rena overhears her speaking with Teppei and discovers Rina makes a living out of lying and scamming people.
- Cruel and Unusual Death:
- In the scenarios where she steals money from the Sonozakis, her mutilated corpse is found washed in the sewers. Her nose and ears were cut off, one nail was driven through each of her finger joints, and her belly was slit open.
- In Tsumihoroboshi-hen, Rena cuts her stomach open and beats her to death with a pipe.
- In Oniakashi-hen, Rina gets strangled to near-unconsciousness, beaten and slashed with Rena's cleaver until she dies, and to further drive it home, her body is cut into pieces and stuffed into separate bags.
- Distinguishing Mark: A red star-shaped tattoo on her belly. Useful for identifying her mangled, rotted corpse.
- Even Evil Has Standards: In Sotsu, while just as conniving and manipulative as before, Rina has an uncharacteristic tinge of regret for driving Rena's father to drink and stealing his money. She's specifically hesistant to keep her scheme going for Rena's sake, not wanting her to be in a difficult situation as a fellow child raised by a single parent. Rina even goes straight to Rena appealing for her to ask her father to stop visiting her club and claims she'll stay away from him. It doesn't take.
- Foreshadowing: In case you don't spot her right from the beginning, the first TIP of Tsumihoroboshi after she appears tells us her name and her work: the same as Teppei's mistress who was killed horribly three arcs earlier. Woops. In other words if she dies early, Teppei Houjou returns to Hinamizawa.
- Gold Digger: In Tsumihoroboshi-hen, she's only dating Rena's father to extort money from him.
- Hate Sink: Like Teppei, she's made unsympathetic and hateable so we feel more bad for Rena when the latter kills Rina as revenge for scamming her father. This is reversed come Sotsu in which she expresses regret for having manipulated Rena's father for cash.
- HeelFace Door-Slam: In Oniakashi-hen, for the first time in series history, Rina regrets the trouble she has put Rena's dad through, presumably due to remembering past loops like Teppei. Unlike Teppei though, she never gets the chance to bury the hatchet with Rena. Rina is instead lured by a H-173-infected Rena to her hangout spot and slashed to death. Just as she's asking Rena to stop her father from visiting her club.
- Karmic Death: In Tsumihoroboshi-hen, she's extorting money from Rena's father, which ends in Rena brutally beating her to death with a pipe. Subverted in Sotsu, where she's killed by an infected Rena as she's apologizing to her for what she did.
- Meaningful Name: Rena took the "i" out of her name to signify the removal of all "ickyness" from her life. Could it really be a coincidence that Rina is nothing but horribleness?
- No Good Deed Goes Unpunished: In Sotsu she regrets the scam and tells Rena about it, asking Rena to help her end it by convincing Rena's father to stop visiting Rina. Unfortunately, Rena takes this genuine act of remorse as another lie and responds by brutally killing Rina.
- Outlaw Couple: With Teppei. Together they swindle men out of their money through intimidation and blackmail schemes.
- Red Eyes, Take Warning: Major hint that there's something not right about her.
- Rose-Haired Sweetie: Subverted. The pink-haired Rina at first presents herself as a nice and friendly woman who loves Rena's father and wants to get along with Rena even though the latter dislikes her. Then Rena discovers that's all an act and Rina's true self is a manipulative, vicious scammer who only wants her father's money and is ready to kill Rena when she exposes her as a fraud. Double subverted in Sotsu, where her regret for bleeding Rena's father dry is genuine and she has sincere intentions to strike a bond with Rena. Too bad Rena's succumbed to the effects of the Syndrome...
- The Schlub Pub Seduction Deduction: It has struck again. Poor Rena's dad.
- Tattooed Crook: She's Teppei's partner in crime and has a star-shaped tattoo on her midriff.
- Too Dumb to Live:
- In Tsumihoroboshi, Rina is lured by Rena to an abandoned junkyard where no one can hear her scream. A junkyard that Rena comes by every day to look for treasures and she thinks she's got the upper hand on Rena. She learned the hard way when Rena beat her to death with a pipe.
- In Minagoroshi, you learn that her potential death can be caused by her attempt at swindeling the yakuza.
- Vigilante Execution: The motive for her death in the Tsumihoroboshi-hen and Oniakashi-hen. Only in the latter, Rina wasn't as deserving of her death.
- Villains Want Mercy: Once Rena outs her as a Gold Digger, she starts strangling her while laughing about how cursed her life has been from her parents' divorce to now. Rena manages to grab a pipe and furiously starts bludgeoning her with it. Now that Rena has the upper hand, she tearfully begs for her life, but only further enrages her by using the name "Reina".
- Would Hurt a Child: She doesn't have qualms with seriously attacking Rena when the latter realizes hers and Teppei's scam.
- You Gotta Have Blue Hair: She has apparently natural pink hair.
Voiced by: Kikuko Inoue (JP), Megan Hollingshead (EN, Bang Zoom), Elizabeth Maxwell (EN, Funimation)
Mion and Shion's mother. Although one of her daughters is still the family heir, Akane herself was disowned after marrying someone of whom her family disapproved.
- Curtains Match the Window: Green hair and eyes, which her daughters got from her.
- Dating What Daddy Hates: She got married to a Yakuza boss from outside the village, which led to the Fingore mentioned below and changing the kanji in her name to remove the "oni".
- Does Not Like Spam: She claims to hate shiitake mushrooms as much as liars.
- Fingore: Akane had to rip off her own fingernails due to her feud with Oryou over marrying a guy the clan didn't approve. Unlike Shion, she can laugh it off now.
- Katanas Are Just Better: Her Weapon of Choice is a katana. Mion must have got it from somewhere.
- Kimono Is Traditional: She's a Yamato Nadeshiko who is always dressed in a kimono.
- Marry for Love: She married an outsider of the village of her own choice instead of letting Oryou choose her husband for her.
- Missing Mom: She's rarely on screen due to her estrangement. Like Shion, she lives in Okinomiya instead of Hinamizawa.
- Nice Girl: While she's calm and collected, in Meakashi, she does held concerns for Shion's wellbeing as she gets her three nails ripped off painfully and is quite warm and welcoming to Keiichi in the manga version of 'Minagoroshi'' as she hilariously willing to have him marry either Mion or Shion if he wants to.
- Odd Friendship: Forms a friendship with Ooishi in Matsuribayashi despite the years of hatred between them, thanks to Ooishi realizing the Sonozaki family had nothing to do with the construction manager's death.
- Odd Name Out: She's the only female of her family not to have the character for oni in her name. She used to, but had to change the spelling of her name when she was disowned.
- Red Baron: The "Demon Princess of Shishibone".
- Shipper on Deck: She assumes that Keiichi's determination to save Satoko from Teppei in Minagoroshi means that they're a couple. When corrected by Mion, she offers him either of her daughters and invites him to start calling her "Mom", only to get smacked by both Mion and Shion.
- Silk Hiding Steel: Oh, you'd better believe it. Despite coming across as calm, controlled, kindly, and even-tempered, Akane is a strong woman and when she puts her foot down, even Mion and Shion don't dare to cross her.
- Yakuza: Her husband is a crime boss.
- Yamato Nadeshiko: Fits the trope to a T, from her traditional kimono garb, to her calm-yet-controlled personality, to her wiliness and resourcefulness in the face of hardship. Even her daughters respect her strength.
- You Gotta Have Blue Hair: She has green hair, which her daughter obviously inherited from her.
Voiced by: Masaaki Tsukada (JP), Kyle Hebert (EN, Bang Zoom), Mike Pollock (EN, Funimation)
The head of one of the Three Families and the official village chief of Hinamizawa. He seems to be a kindly old man, but is vehement in his hatred for Hinamizawa's enemies.
Voiced by: Kazumi Tanaka (JP), Charlie Campbell (EN, Funimation)
A scientist who devoted his entire life to researching a disease he calls Hinamizawa Syndrome, which he thinks could shake the entire scientific knowledge about the human brain. However, his research is shunned and mocked by the academic world.
- Alphabetical Theme Naming: His first name is written 一二三 (one two three). Then Miyoko became Miyo (三四 three four).
- Deceased Parents Are the Best: His adopted granddaughter only has wonderful memories of him and nearly idolizes him even years after his death.
- Doting Grandparent: He doted on his adopted granddaughter and practiced fun breathing exercises with her.
- Driven to Suicide: When he realized he was going senile in his late years, Hifumi jumped off the roof top of the hospital where he was admitted at.
- For Want of a Nail: The one timeline where Miyoko's parents survive and Hifumi's endless efforts in researching Hinamizawa Syndrome pays off is the one portrayed in Outbreak... where the Japanese government uses his research as basis for turning Hinamizawa Syndrome into a weapon of biological warfare.
- Godhood Seeker: Downplayed. He just thinks that if his research is acknowleged, he will become some kind of eternal being, just like a god. The problem is, his beloved granddaughter took it a bit too seriously. His final letter to her really didn't help though as he asked her to become a god because he couldn't.
- Just in Time: Had he come to the orphanage only a day later, Miyoko would probably have died with her head in that latrin.
- Parental Substitute: He adopted Miyoko after the death of her parents and raised her as her own child.
- Posthumous Character: Died several years before the start of the story.
- Small Role, Big Impact: Even though he only appears in a flashback during the final arc, he and his research are the biggest motivators of the Big Bad in the story.
- Unwitting Instigator of Doom: You don't understand the first time (because it seems irrelevant in that arc), but the first TIP of Minagoroshi is his suicide letter to Miyoko. He tells her that he coudn't become a god and that she must become one in his stead. Worst. Will. Ever.