Strange Houses

Originally published in 2021, Strange Houses is a horror mystery novel by a Japanese author and YouTube content creator who goes by the pseudonym Uketsu. The novel began as a YouTube video in which Uketsu and an architect friend discuss an unusual house floor plan and end up realizing the troubling implications of its design. The viral success of the video led Uketsu to write and publish a novelized version of the story. In 2024, the novel was adapted to film under the title A Strange House. It was directed by Jun’ichi Ishikawa and starred Shôtarô Mamiya and Jirô Satô.

The novel follows a writer named Uketsu, who is asked to examine the unusual floor plan of a Tokyo house. Uketsu’s draftsman friend, Kurihara, poses the troubling theory that the house may have been used to murder people. The friends’ quest for the truth examines The Corruptive Power of Greed, The Inaccessibility of the Truth, and The Struggle to Make a Better Life.

This study guide refers to the Kindle edition of the novel, translated into English by Jim Rion and published by HarperVia in 2025.

Content Warning: The source material and guide feature depictions of graphic violence, death, illness, substance use, addiction, ableism, child death, emotional abuse, bullying, mental illness, child abuse, death by suicide, self-harm, pregnancy termination, and sexual violence.

Plot Summary

In September 2019, a man named Yanaoka consults his friend, a writer named Uketsu, about a Tokyo house where he is thinking of settling with his pregnant wife. The house, which was previously owned by a family of three, suits Yanaoka’s needs, but Yanaoka is bothered by the existence of an unusual dead space built into the kitchen wall. Uketsu turns to another friend, a draftsman named Kurihara, to review the house’s floor plan.

Uketsu and Kurihara observe several unusual details about the second floor of the house, including its enclosed child’s room and its bathroom, which is windowless and separate from the bedrooms. When Uketsu theorizes that the kitchen dead space is a secret passage between the child’s room and the bathroom, Kurihara proposes an even bolder interpretation: The couple in this house lured guests to the second-floor bathroom, where they would send the child, whom they kept prisoner, to kill the guest. The family would then dismember the guest’s corpse and use the house’s secret passages to transport the pieces to the garage before disposing of the remains elsewhere.

When Uketsu calls Yanaoka to advise against the purchase, Yanaoka tells him that he already backed out because a dismembered corpse was found near the house. The corpse was missing its left hand, which strikes Uketsu as a peculiar detail. He becomes fixated on uncovering the truth and writes an article to explain Kurihara’s interpretation. 

Soon, a woman named Yuzuki Miyae contacts him, claiming that her husband, Kyoichi, was killed in the manner Uketsu described in his article. Miyae, who lives in Saitama Prefecture, explains that three years earlier, her husband disappeared. When his remains were finally discovered, Kyoichi was missing his left hand. Miyae shares her theory that the family in Uketsu’s article used to live in a similar house in Saitama. Like the Tokyo house, the Saitama house includes an enclosed child’s room that gives the occupant discreet access to a bathroom on the first floor. 

Uketsu visits the Tokyo house to understand why the family might have moved there from Saitama. He learns that the family is called Katabuchi and that they have an infant son. Shortly before they moved out of the house, a neighbor spotted an older child in one of the Katabuchis’ windows—possibly the child they have coerced into committing murder. 

Just before Uketsu is about to present his findings to Miyae, Kurihara warns him that Miyae may be lying about her identity. Miyae quickly admits that her real name is Yuzuki Katabuchi and that she is the sister of the woman who lived in both of the houses. Yuzuki seeks to reunite with her sister, Ayano, who was expelled from the family when Yuzuki was very young. Yuzuki only reconnected with Ayano in adulthood when Ayano reached out to her. As they kept in touch, the sisters expressed their shared hope for a reunion, which wouldn’t occur until 2019, when Ayano and her husband, Keita, were living in Tokyo. Not long after Yuzuki’s visit, the Katabuchis vanished, leaving Yuzuki worried about her sister’s fate.

Kurihara probes the reasons behind Ayano’s expulsion from the family. The week before Ayano was expelled, her cousin, Yoichi, died at their grandparents’ house under mysterious circumstances. Drawing a floor plan from memory, Yuzuki explains how Yoichi was found dead before a Buddhist altar maintained by her grandfather. Yuzuki doubted the claim that Yoichi died of an accidental fall. 

Kurihara posits that, like the Saitama and Tokyo houses, the grandparents’ house contained hidden rooms and passageways designed to support ritualistic murder practices. Yoichi’s murderer leveraged their knowledge of these passageways and ritualistic practices to abduct Yoichi and kill him. Kurihara theorizes that Yuzuki’s father was Yoichi’s killer, possibly motivated by the desire to prevent Yoichi from inheriting the familial estate after his grandparents’ death. He also believes that Ayano was delivered to her grandparents so that she could be indoctrinated into their ritualistic killing traditions.

Yuzuki’s mother, Yoshie, reaches out to her to explain the truth about their family. Yoshie shares a letter that she received from Keita, who revealed the history of his relationship with Ayano. In high school, Ayano was the only person who extended sympathy to Keita, a frequent target of bullies. They soon started dating, though Ayano remained secretive about her life outside school. Before graduation, Ayano revealed that she was involved in a ritual called the Offering of the Left Hand.

The Offering of the Left Hand dates back to the turn of the 20th century. When the Katabuchi family head, Kaei, selected his eldest son, Soichiro, to succeed him over his more-competent and younger son, Seikichi, Seikichi broke away from the family to start his own business. The rationale for Kaei’s choice was that Seikichi was an illegitimate child from an affair. Kaei remained involved in the family business to make up for Soichiro’s weaknesses. He also arranged Soichiro’s marriage to a woman named Ushio.

When Kaei died, Soichiro’s life quickly entered a downward spiral. Not only did his business fail, but Ushio discovered that Soichiro was involved in an incestuous affair with his sister, Chizuru, who became pregnant with his child. Ushio died by suicide, cutting off her left hand. When Chizuru gave birth to twins, Soichiro was shocked to find that one of them, Momota, was born without a left hand. A shaman named Rankyo later convinced Soichiro that Ushio had cursed his family line. To remedy the curse, Rankyo instituted the Offering, which demanded that Soichiro raise Momota to kill one of Seikichi’s descendants annually while Momota was between the ages of 10 and 13. The twin who was born with a left hand would serve as Momota’s warden throughout his indoctrination. Yoshie later discovered that Rankyo was related to one of Seikichi’s several wives and had fooled Soichiro into carrying out the ritual to eliminate other heirs to Seikichi’s fortune.

Soichiro’s third child, Shigeharu, lived in relative comfort without having to perform the Offering for many years. This changed when he learned that his daughter-in-law, Misaki, would soon give birth to a child who was missing his left hand. Fearing that Ushio’s curse would lead to the loss of his wealth, Shigeharu became determined to observe the tenets of the Offering. When Yuzuki’s parents learned that they had a faint relation to the Seikichi family line, they feared that Shigeharu would select one of their children as a ritual sacrifice. Yuzuki’s father thus killed Misaki’s eldest son, Yoichi, to prevent him from carrying out the ritual. Consequently, Shigeharu abducted Ayano to serve as the warden of Misaki’s second child. However, Ayano’s maturity enabled her to resist Shigeharu’s indoctrination. 

After Ayano shared her family history with Keita, Keita devised a plan to liberate Ayano from Shigeharu’s grasp. First, he married Ayano so that he could serve as her co-warden. Shortly before Misaki’s child, Momoya, turned 10, Keita requested that he and Ayano live in a house of their own, where they promised to carry out the ritual. There, he could deceive Shigeharu into believing that they had completed the ritual while raising Momoya away from his influence. A year later, Ayano gave birth to her son, Hiroto. Keita separated the children, afraid that Momoya might harm Hiroto. When Shigeharu discovered Keita’s deception, he sent his enforcer, Kiyotsugu, to collect Momoya from the couple. To Keita’s surprise, Momoya doted on Hiroto, inspiring Keita to defend Ayano and both children from Kiyotsugu. A news report reveals that Keita is now a fugitive from the law, having been named as the prime suspect in Kiyotsugu and Shigeharu’s deaths.

Yoshie and Yuzuki reconcile, resolving to work together to support Ayano and the two children. Uketsu shares what he has learned with Kurihara, who cannot help but point out the holes in Yoshie’s story. He speculates that because Yoshie had a faint relation to Seikichi’s family line, she might have been involved in a counter-ritual to destabilize the Soichiro family line. 

In an afterword, Kurihara reveals that Uketsu left out a key detail from his narration of the Tokyo house discussion. Kurihara speculated that Ayano may have been keeping Keita prisoner. He points out that the identity of the dismembered corpse was never revealed and that there is no proof that Keita wrote the letter that Yoshie received. He ends by reminding the reader that this is all mere speculation.