After visiting an abandoned building, one of Haruka Ozawa's friends appears to be possessed by a spirit, and another commits suicide. In desperation she turns to Yakumo Saitou, a lackadaisical college student who is rumored to have supernatural abilities. Born with one red eye through which he can communicate with the dead, he agrees to solve Haruka's mystery, for a fee. Haruka remains skeptical, until Yakumo conveys a message to her from her dead twin sister. Yakumo begins to investigate and asks for some help from a detective he knows, Gotou Kazutoshi, who then becomes involved in the case when Yakumo uncovers that the hauntings are actually the result of a serial killer. The killer fearing being discovered kidnaps Haruka and sets fire to the building to cover up his crimes. Yakumo figures out where Haruka is taken to with help from her deceased sister and comes just in time to save Haruka. However the culprit escapes and sets fire to the building. Yakumo and Haruka escape the fire, and the killer is arrested by Gotou.
During the night, two constructors begin fixing a new building near a temple for their boss President Irie, when they see a ghost. The scene returns to Haruka coming to see Saitou to bring him her possessed friend Miki. Saitou tells the spirits on her body that the killer is dead, the spirits leave and Miki regains her conscience. After that they go on the bus together Saitou leaves first going back to the university and Haruka leaves for her part-time job. There Haruka serves President Irie and his friend Kunimatsu. She hears about the Fox curse that has been haunting the building/temple from Kunimatsu. After work she goes to the building and to her surprise meets Saitou's uncle and his home which is a temple. She continues to stay and also meets Irie. Irie was picking up a wooden block that had words written on it from his dead lover. There they hear a little girl laughing and the lights breaking which causes Saitou to save Haruka. Saitou was there to investigate the haunting and deduced they were man-made. Kunimatsu, who was in a shed near them, engineered the hauntings to stop Irie from moving the shrine. Irie tells Saitou and Haruka about his love and how he wants to meet her again. Saitou tells him that she had been waiting there for him all along. Suddenly the fox curse appears and turns out to be his lover. Together they meet and everything is solved.
Yakumo takes up a case regarding the death of a school boy and, Haruka tells him of an experience she had when a co-worker was driving her home through a tunnel. Yakumo begins to believe he can only see spirits but nothing more, and so he cannot help them all the time. Yakumo also considers the lives of people around him (especially Haruka's) that he is endangering.
After stopping to help a man lying in the street, Hijikata Makoto (a reporter and daughter of the chief of police), is possessed by the man's spirit once he passes away. The next day Haruka is asked by a girl to investigate the death of a schoolgirl named Ayaka. While Yakumo is asked by Gotou to investigate the possession of Hijikata as a plea from the chief. While investigating the death of the schoolgirl Ayaka, Haruka saw the ghost of the schoolgirl and fell into the river while trying to communicate with the soul. She was saved by 2 policemen and taken to a clinic to recover. Coincidentally, Gotou and Yakumo were also at the clinic to ask Dr Kinoshita some questions about their investigation.
Ayaka is the daughter of Dr Kinoshita who died during a typhoon and drown in the river. The doctor was also close to Dr Andou Takashi (the ghost possessing Hijikata Makoto). Gotou and Yakumo revealed that they connect Dr Kinoshita to Andou from a photo in Andou's belongings. There was also 2 keys in his belongings. One led to a locker with a bag full of money. Gotou and Yakumo managed to track the 2nd key to a storeroom near a dam. They found a missing girl Hashimoto Rimu along with belongings of 2 murdered young girls. The police believed that Dr Andou was the murderer of the 2 girls.
Yakumo and Haruka investigate the haunting of an apartment rented cheaply by a university student, Date Shota. Through the realtor, they learnt that the previous tenant, Shiobara Kimiko had died of natural causes in the apartment and is now haunting it. Yakumo was able to communicate with her ghost and she requested for a letter (hidden behind the mirror in the room) to be burned. Haruku broke Kimiko's request not to read the content of the letter and saw a photo of Kimiko in it. Despite that, Kimiko was sufficiently pacified and wish Haruka well before her spirit departed.
Detective Gotou enlisted the help of Yakumo to investigate a supposedly ghost video taken at Nanase Mansion, where 4 members of the Nanase family was murdered 15 years ago. The video was obtained by Hijikata Makoto and filmed by a scriptwriter Hoshin Yukiko. Yakumo went off and investigate on his own after watching the video. While interviewing Hoshin, Gotou noticed that she resembles the woman seen with Yakumo's father but was unsure of his observation. Gotou and Yuutarou investigated the Nanase Mansion where Gotou was attacked by Miyuki Nanase (the same woman with Yakumo's father). Miyuki was apparently kidnapped on the day of the Nanase family massacre but has remained missing since. Yakumo tracked down the place where the ghost video was filmed and was also attacked by Miyuki, who claimed to be bringing the darkness to him and wants to destroy him.
Yakumo and Detective Gotou are still missing. Makoto and Yuutarou contacted Haruka and discussed with Yakumo's uncle, Isshin on finding Yakumo. Haruku figured out that the ghost video was not shot at the Nanase mansion and both Makoto and Yuutarou also verified that Hoshin Yukiko was a fake. Isshin revealed that the ghost in the video is Yakumo's mother, Azusa. He related the story of how Azusa was kidnapped and held captive when she was young. She eventually escaped two weeks later and was assisted by Haruka's mother, Keiko. They continued to keep in touch and Isshin had an unopened letter from Keiko to Azusa. The letter revealed that Azusa's fiancée is Shunsuke Takeda, who is a suspect in the Nanase Family Massacre. Meanwhile, Miyuki (the woman with Yakumo's father) was seen outside Haruka's apartment and is planning to capture her to torture Yakumo further. Shunsuke Takeda also appeared to protect Haruka and had lured to the police and managed to scare Miyuki away.
Ishii finally figured out the identity of Miyuki as the woman with Yakumo's father. After interviewing her tutor, Ishii and Hijikata find Detective Gotou in a secret room within the Nanase Mansion, with a little help from Takeda. After untying Detective Gotou he says that Takeda's spirit told him that Yakumo's father was going to kill Haruka in front of Yakumo. Takeda's spirit also told Haruka that Yakumo is in Nagano. She calls her mother and travels to Nagano, to the place where Yakumo's mother was raped. There she finds Yakumo tied to a chair with wounds on his chest. Haruka thinking that Yakumo was dead and starts crying and yells "Don't give up!". Yakumo was alive but weak from the drugs. They leave the house together, but Miyuki appear and tried to kill Haruka. Detective Gotou and arrive on the scene. It was revealed that that woman is actually Nanase Miyuki, the real culprit in the Nanase Quadruple Murder. Yakumo's mother's spirit appears and helps them by detaining Nanase.
Haruka and Yakumo accompany Haruka's mother to the train station. She tells them that she will send them something, but they did not hear what as the train door was already closing as she was telling them. Hijikata Makoto is then shown talking to a doctor at a hospital. The doctor tells her of a ghost appearing and asking patients when they will die. Hijikata promises to relay this case to and expert she knows (Yakumo) and begins to leave running into Saitou Isshin and Nao. Isshin tells her that he is there to consult a doctor because of frequent headaches. While he is there he meets a young girl in a wheelchair and they discuss what happens after death. After comforting her he asks her to become friends with Nao. Meanwhile, the hunt for the culprit of the murder case of Quadruple Nanase, Miyuki Nanase, ends with her being captured by the police. While in jail she believes that Yakumo's father will come and give her freedom, once again (as he did when she was young).
Gotou and Ishii rushed to the shrine to protect Isshin; but he knocked Gotou out before confronting Yakumo's father on his own. He was subsequently stabbed, apparently by Yakumo's father. Meanwhile, Haruka and Yakumo proceeded to the hospital to investigate the ghost of the girl. They encountered her apologizing to the patient she has previously confronted. Haruka and Yakumo eventually learnt of Isshin's injuries. Due to the extensive lost of blood, he was declared brain dead by the doctor. Gotou took Nao back to his house to be looked after by his wife. Ishii has deduced and forensic evidence suggest that Yakumo's father may be a spirit but one who is able to interact with the physical world. He possessed Miyuki so that she could be sent to the hospital.
Haruka and Yakumo saw the ghost of the little girl over Isshin and followed it to the room of Mamiya Yoshiko, the little girl in the wheelchair that Isshin met in the hospital. Yakumo found out that Yoshiko is the daughter of the Prof Sakakibara, the attending doctor on the night that Isshin was attacked. He found further proof that Prof Sakakibara was the actual attacker of his uncle (from the damaged mirror that he side swiped when he was rushing back to the temple). His motivation for attacking Isshin was so that his organ could be harvested (Isshin is a registered organ donor) and used to save his daughter. Yakumo managed to corner Sakaibara on the hospital heli-pad. Gotou, Ishii, Haruka, Nao and Makoto arrives shortly after.
Miyuki shot Gotou in the stomach to generate hatred within Yakumo so that his father's spirit can attempt a possession. Miyuki explained that the purpose of luring Yakumo to embrace the darkness is to ensure that his state of mind is practically the same as his father, allowing his father and his soul to merge and for his father to take over his body. Yakumo appeared to be possessed by his father as both his eyes is now red; but he has tricked Miyuki by using his uncle's red contact lens. He managed to disarm Miyuki but she managed to escape. Yakumo's father vow to continue to pursue his objectives. Yakumo gave his consent to sign the organ release form to save Sakaibara's daughter; but on the condition that Sakibara turned himself in to the police.
