Written and illustrated by Masakazu Ishiguro, Heavenly Delusion started in Kodansha's seinen manga magazine Monthly Afternoon on January 25, 2018.[1] Kodansha has collected its chapters into individual tankōbon volumes. The first volume was released on July 23, 2018;[2] a promotional video, directed by Tasuku Watanabe, for the first volume was released on the same date.[3] As of October 22, 2024, 11 volumes have been released.[4]
The story is divided in two storylines with one involving the characters Maru and Kiruko as they travel across a post-apocalyptic world, while another story focuses on a group of children who live in a school. In the outside world, 15 years have passed since an unprecedented disaster completely destroyed modern civilization. A group of children live in a facility isolated from the outside world. One day, one of them, a girl named Tokio, receives a message that says "Do you want to go outside of the outside?" Mimihime, another girl who lives in the same facility, has a prediction and tells the upset Tokio that two people will come from the outside to save her, one of whom has the same face as her, while the director of the school tells her that the outside world is Hell. Meanwhile, a boy named Maru, who looks just like Tokio, is traveling through this devastated Japan with a girl named Kiruko, in search of Heaven.
In North America, the series is licensed in English by Denpa.[5] The first volume was released on December 31, 2019.[6]
In a school, several young students are being observed by their teachers. One student, Tokio, is attracted to the artist Kona and keeps several drawings he makes which are found unreal by another one. The story then moves to young boy similar to Tokio named Maru who is travelling alongside his bodyguard Kiruko to find a place known as Heaven to inject a similar person with a drug. During their journey, they are allowed to rest into a woman's house. However, in the night they are attacked by monster labeled as Hiruko who kills the woman. Maru manages to kill the Hiruko with a supernatural ability he possesses. The duo continue their journey to Heaven until they are welcome by a family of farmers from the Kusanabe Plantation. As they rest, Maru tells Kiruko he likes her but the latter claims she is actually a man with a female body.
Kiriko Takehaya was a famous racer who lived with her brother, the rebellious Haruki, and a group of orphans assisted by Robin Inazaki. During the attack of a Hiruko, Haruki suffered severe wounds, losing all his limbs. His brain was then transplanted into Kiriko's body. Now known as Kiruko, she started searching for her missing friends. After telling Maru this, the duo finds themselves attacked by a fish-like Hiruko. With Kiruko out of firepower, she and Maru are chased by the monster until it is altered by the marijuana hidden inside, leaving Maru to perform the finishing move on the creature. Meanwhile at the school, Tokio sees a group of faceless babies. Shortly after that, a fellow student named Tarao suffers a disease and tries to kiss Tokio. After leaving the ship, Maru and Kiruko continue their journey on foot where the former gets into a fight with delinquents.
Fearing another fight, Kiruko hides Maru in a room while she sells items she has found. Meanwhile, Tarao passes away due to his terminal disease much to the shock of the students with Kona remembering another late student, Asura. As they comfort each other, Kona and Tokio start a relationship. Back during their search for Heaven, Maru and Kiruko hunt a Hiruko only to be shocked by the fact it is a wild bear. Nevertheless, they kill it through teamwork. As they rest in an inn, the young owner named Totori tries to seduce Maru who instead discovers she has the heart of a Hiruko. The next day, Maru and Kiruko leave the city and meet a man who wants to hire him to take to the Immortal Order which is doing experiments with human lives to create immortal creatures. Though the man gives up, the duo decides to investigate it to search for Kiruko's doctor, Sawatari. They meet the Liviuman who oppose the Order's methods and accept the job of investigating. As they enter the building, two are approached by small Hirukos.
Kiruko is trapped in a hallucination by the enemies until Maru wakes her up with a kiss and eliminates all the creatures. They are then met by a man wearing an eye patch who says he is Dr. Usami and he asks for their help. One of the human experiments wishes for a mercy kill by eliminating the Hiruko inside her body that has left her alive. Maru agrees but is shocked when Usami kills himself afterwards. Before leaving, Kiruko learns that Robin is still alive and she goes on a search to find him. Meanwhile in Heaven, Tokio fears something bad is going to happen to her body while Kona remembers Asura's suicide. The adults develop a gun identical to Kiruko's as she and Maru meet a man named Juichi. He gives them multiple theories to what caused the tragedy in the world and that there was a sect that advocated female supremacy, which they believe is Takahara Academy due to it having the same logo seen on Kiruko's gun. The Heaven leaders are in a commotion when learning Tokio is pregnant and wish to know the father's identity.
Kiruko and Maru investigate one empty Takahara Academy facility as they believe it is connected to Heaven. The two are interrupted by Juichi who is investigating it too to find a child in the facility. However, they reach another empty building where they attacked by a Hiruko able to freeze the area. After Kiruko takes it down, one of Juichi's allies reveal they found the missing child, his son. Kiruko and Maru are later attacked by the Hiruko again, whom they realize is actually Juichi's son and manage to calm him down. The next day, Kiruko and Maru are offered a vehicle by Juichi and continue their journey, though the man kills one of his allies. Meanwhile in Heaven, after Tokio gives birth to a child, the Director aims to transplant her brain in order to increase her lifespan. Mimihime interacts with the new students but one of them gives her hallucinations. Kiruko and Maru find information of Robin in another city and split up so that the former can talk with her old friend.
Although Kiruko wishes to know what happened to the ones from Funayama Orphanage, Robin is shocked about the brain transplant, believing Dr. Sakota is responsible. As Kiruko prepares to rest, Robin instead sexually assaults her. Unable to wait more, Maru goes back to the city by force and learns Robin violated Kiruko. Enraged, Maru is beats him up until leaving him nearly dead. A free Kiruko asks Maru to stop the attack. Meanwhile, in the Academy, Mimihime fears the visions she suffers about students turning into Hirukos. As Maru and Kiruko leave the laboratory, people discover experiments involving Hirukos and corpses and ask a mercenary named Takezuka to find the related people. The academy is then attacked by an unknown chaos that wounds Shiro while protecting Mimihime and they proceed to escape. A doctor manages to protect Tokio's children but cannot tell the identity of each and marks one of them with a circle. He claims the marked child should be given to Tokio much to the staff's confusion though the director claims another.
Kiruko and Maru meet a young girl named Helm as the latter senses Hirukos in the area. As Helm explains she was once violated by an elder, the duo helps her get revenge with such man. In the academy, several of unknown flying individuals leave the place for an operation while Kona finds Tokio with their child. Several military men attack the area forcing the teachers to hide. In the aftermath, the students are confused about their class Sacchio who has no knowledge of her memories and instead calls herself Mikura. Meanwhile, Anzu, Tata, Shiro and Mimihime have become used to the civilization after the attack to the academy made them escape to from Heaven. but experience a major earthquake.
The earthquake has caused a major impact in the world in the past. Meanwhile, Maru and Kiruko spend time with a family as the former detects another Hiruko which is sealed in the sanctuary since the Edo Period. When the elder refuses such action, the duo instead to the Hamatsu Airport. Meanwhile, it is revealed that Takezuka is but an hermaphrodite raised in Takahara by doctor Teruhiko Sawatari who struggled after the earthquake; the director when missing but and the doctor was confused if Tokio's child was the right one or a clone. Sawatari eventually learned that the Takahara is behind the world's end as they sent unknown creatures into space which would cause an asteroid to hit the planet. Meanwhile, Mikura is revealed to be the Academy Director Shino Kaminaka using a new body as vessel. She goes with her classmates in a quest to find the ideal paradise. As time went on, Michika met a married Taka and would eventually find Kiruko and Maru.
Taka tries to kill Michika as he finds him dangerous but he is instead decapitated by his foe. Upon finding Kiruko and Maru as ordered, Michika convinces Maru to fight him for fun and once again remains victorious. However, the other people working alongside her fail to arrest the duo. In the next day, Michika once again convinces Maru to fight, telling him she will explain everything they need if he wins. This time Maru realizes Michika has a notable perception to movements just like him which makes the rematch result in both fighters receiving multiple hits. Eventually, a satisfied Michika gives up and leaves with Kiruko being confused about Michika's answers who claims they are all Hirukos. As Maru rests, Kiruko meets Teruhiko Sakota who transplanted her brain years ago after Kiriko was shot in the head. However, Kiruko believes her sister's existence remains safe. As three days pass, Maru recovers and agrees with Kiruko's plan of helping with the Hiruko extermination. Sakota is shocked to see Maru, wondering if he is actually his brother Yamato and if he know his parents are Tokio and Kona. However, Maru has no memories of a family due to being put in an orphanage at young age. Sakota, revealed as Sawatari, takes the duo to Anzu to stop the Man Eater but dies when fighting leaving it to the teenagers to use their skills to stop it.
After Michika helps Maru finish the ManEater. The two travelling teenagers meet Doctor Yuko Aoshima who used to work in Takahara Academy with Sawatari and believes the two should find Maru's missing family to give them an unknown medicine from Mikura in Izukunoe Island. The two receive a robot, Nata, from Heaven in the band with aid about their location. The series' timeline then moves to the past where a man named Toru worked for a gang and a young Robin lived peacefully with his younger sister Marin. Back into the present, Kiruko and Maru travel to Osaka to find a Funayama Orphanage and find an area called New Heaven where Bandits Ohwl befriend them. A manga artist offers them the location of its former residents in exchange of help. The two accept and go into Izukunoe Island. As the duo finish their job, an older Toru appears.