Seasons & Episode
Mai meets Naru while exchanging ghost stories with her friends, and learns her school principal has hired him to investigate an allegedly haunted school building. Mai later causes the injury of Naru's assistant and is forced to stand in as a temporary replacement. The principal also brings in several exorcists and mediums, and more help arrives in the form of a classmate of Mai's, who claims to have the ability to sense spirits.
Each member of the team proposes a different theory as to what is responsible for the odd occurrences. After collecting data overnight, Naru begins to doubt the presence of any spirits and instead theorises that land subsidence is the cause of all the ghostly activity. Mai's classmate, Kuroda, fiercely insists that a poltergeist is at work, and evidence appearing to support her idea soon arises.
After disappearing for a night, Naru conducts an experiment involving all those associated with the case. He implants a hypnotic suggestion in their minds regarding a chair in a sealed room moving overnight. His experiment proving successful, Naru reveals his explanation for the latest developments, correctly accusing one of the group of mimicking a poltergeist's acts. After the conclusion of the case, Naru offers Mai a part-time job at the SPR, which she accepts.
Ayami reveals Minnie has been exerting a strict control over her, punishing her whenever she breaks a promise to Minnie. The team believes the doll is being used as a vessel by a spirit. After Ayami is involved in a near-fatal accident, Naru discovers previous residents of the house have been plagued with frightening incidents, all resulting in the death of young children.
The SPR are asked to handle a case at the Yuasa High School, where a series of unusual events are seemingly related to a cursed desk and a haunted clubroom. Rumours circulating the school population implicate a girl with psychokinesis, who had previously vowed to 'curse to death' all the doubters of her gifts.
The team arrive at the conclusion that the sheer number of occurrences at the school would require a psychic power far greater than anyone could possibly possess. Coupled with Masako's insistence the school houses no spirits, Naru begins to believe someone is using a form of voodoo, calling on gods to carry out their desires. The discovery of human-like dolls under the desk and in the clubroom seem to confirm this.
Evidence against the psychokinetic girl, Kasai, begins to pile up. Mai refuses to believe Kasai is responsible, despite Bou-san and Ayako's beliefs to the contrary, saying she has a feeling within her that Kasai is innocent. While searching for more dolls, Mai is lured to an open manhole by the ghost of a crying child. Naru fails to save her from falling in and instead, they both find themselves inside the hole.
Bou-san, Ayako, and Mai destroy the dolls, effectively removing the 'curse' on the school. Naru is sent to the hospital as a result of the manhole accident, where he makes a startling revelation regarding the past of someone at the school. He clears Kasai's name, but is forced to accuse someone close to her in the process. After the case, the team return to the SPR, where Naru successfully tests Mai for psychic abilities.
Masako requests Naru investigate a park where over six months, couples have had water dumped over them from thin air. The team, excluding Lin, split up at Masako's suggestion into pairs and they soon attract the spirit of a woman. Taking possession of Masako's body, the woman explains she died soon after being cheated on by her boyfriend. Mai convinces her to let go and move on to heaven, but not until they have forced the cheating partner to acknowledge the hurt he caused.
John brings the SPR their next case on Christmas Eve. Children at a local church are being possessed by the ghost of a mute boy who vanished one day during a game of Hide and Seek. The boy, Kenji, hides in the woods once he claims a body. While in control of a child, he mistakes Lin for his dead father and clings to him. John exorcises Kenji from the child he resides in, but Kenji then promptly possesses Mai.
While Naru searches for Kenji's body, Lin is ordered to play with Kenji. Lin snaps shortly after and Kenji, still in Mai's body, races into the woods. After John and Bou-san find Kenji, Naru tells him his father is waiting for him in heaven and asks him where he is. Kenji shows him the place he'd hid and died in and releases Mai, who sees Kenji's tragic death in a dream.
The highly publicised Ryokuryou High School is brought to the SPR's attention when students report a series of terrifying events, including a ghostly dog attacking them. The SPR gathers information with the help of the school valedictorian, Yasuhara, and learn the incidents began after Sakauchi, a first year student, committed suicide. During the installation of cameras around the school, Mai encounters Sakauchi's ghost.
Naru and Lin begin a ritual to return the curse to its casters, thereby leaving leaving the curse's target unharmed. Mai learns that this ritual will affect most of the school's student population, as they, while unknowingly, contributed to the curse. Her attempt to stop it fails, but Naru and Lin are able to lift the curse with little harm to the students.
Madoka, an associate of Naru's, requests the SPR take on a case for the former Prime Minister and investigate the mysterious disappearances of young people at one of his properties. Before the case, Naru asks Yasuhara to pretend to be SPR's director in his stead. The SPR team join two other teams of investigators, one of which requests they all participate in a séance which has an unexpected result.
Members of the other teams begin disappearing. In a search of the house, John finds a secret room that enables the SPR team to add to the information they learned from Madoka of the estate's past owners. Shortly after, Mai has a dream in which she experiences first-hand the death of someone from the estate.
The dream leaves Mai traumatised, but prompts new speculation by the team regarding the house's spirits. Lin carries out a ritual to summon the spirit of one of the missing people, who gives the SPR team a new lead. The discovery of one of the missing people's corpse induces Oliver Davis, one of the investigators on another team, to reveal himself as an impostor.
Nao, a member of the family involved, is confirmed dead and Masako is sent to perform a ritual. Mai has another dream and is woken by Masako when a fire spreads in the main house. Another family member meets a tragic end after being possessed. An army of zombies soon enters the SPR's base to free the spirit that has possessed Naru.
Telling ghost stories is a favorite past time of Mai Taniyama and her friends—that is, until she meets 17-year-old Kazuya Shibuya, the man sent by Shibuya Psychic Research Center to investigate paranormal activity at a supposedly haunted school. When Mai gets caught in a dangerous situation, she is rescued by Kazuya's assistant. Saving her lands the assistant incapacitated, and Kazuya demands that Mai become his assistant, instead...