In an isolated region of Kyushu lies the town of Suiten. Though seeming small and modest, Suiten is not a picturesque place for a vacation, unless it is from the “Unseen World”. Taro, Makoto and Masayuki, three boys with traumatic pasts, learn to let their souls cross between the two parallel worlds. However, the Unseen World is no mere copy of the real Apparent World. The Unseen World is the home of ghosts, but changes are now allowing the souls of the dead to pass over into the Apparent World with unpredictable effects. Follow the journey of Taro, Makoto and Masayuki, as they cross between the two worlds, trying to unravel a great mystery.
Tarou has a recurring dream where he is flying and sees his sister with a strange girl. In school, he meets a new transfer student, Masayuki Nakajima. When Tarou falls asleep in class, he begins to dream and remembers a traumatic experience from his past.
At school, Masayuki questions Tarou about his past and the traumatic events from 11 years earlier. Tarou begins to search for answers from his dreams and visits a shrine he thinks he saw.
Tarou and Masayuki begin hanging out. Masayuki, who is afraid of heights, tells Tarou to try to confront his fears. When Tarou decides to do so, Masayuki joins him and brings someone else along.
Tarou, Masayuki and Makoto go to explore the abandoned hospital. They search for the room where Tarou was held--supposedly a cursed chamber. As they walk around, strange things begin to happen all around them.
After having an out-of-body experience in the hospital, the three try to go about their normal lives as if nothing unusual has happened. Tarou's counselor comes to his home to meet his parents and notes that there is something odd about his mother. Later, the boys encounter the Unseen World.
In the Unseen World, there is a man who can see Tarou and Masayuki when nothing else can. Back in their own world, they go in search of answers. Masayuki tries to confront his greatest fear.
Tarou has an accident and ends up in the hospital. Masayuki visits him there, and the two boys meet with Dr. Atsushi and Dr. Reika.
Dr. Atsushi reviews what he has discovered in his two months as Tarou's counselor. Tarou has another out-of-body experience which reveals many clues to him. Dr. Atsushi believes that Tarou's experiences are a psychological result of the trauma he has suffered. Makoto is still trying to find more information about his late father and visits the Komagusu.
A dark ghost appears near the place where Tarou's kidnapper was killed. More and more people are beginning to take notice of the strange events that are happening. Tarou and Masayuki hope that these events will help them in uncovering the true identity of Tarou's abductor.
Masayuki has become the target of bullies until Makoto steps in. Tarou discusses a new type of therapy in his session with Dr. Atsushi. Later, Tarou and Masayuki visit the shrine to see if there they can find out more about the Unseen World.
Tarou's experiences have become so common that he no longer is disturbed by them until he sees a body floating near the dam. Masayuki and Makoto accompany Tarou to investigate. There may be a connection there with the events that took place in the abandoned hospital.
The boys have an ordinary day at school even though Makoto can't stop thinking about his mother. Tarou meets with Dr. Atsushi, and they talk about homeostasis and the struggle for balance. After his session, Tarou runs into Miyako and the two talk about their experiences until Miyako goes into a trance.
As he sleeps, Tarou has another experience: he goes into the past and visits Kameiwa hospital. While there, he meets a stranger named Snark. Afterwards, the three boys go to the shrine to visit Miyako.
Makoto's grandmother tries to tell him something important, but he is not interested. At school, the boys ruminate over what Miyako meant about being possessed. They are not the only ones who are discussing Miyako; Dr. Atsushi and Dr. Reika have also taken an interest in her and cut Tarou's counseling session short to meet with her.
Tarou takes a bus to Kumada to apologize to Kei. Makoto is also traveling that way, and the two discuss their suspicions about Miyako. Masayuki and Michio find a photographer sneaking around near the Oogami temple and try to get more information.
Tarou accompanies Makoto to confront his mother. Masayuki and Michio try to find more information on DBI and its research when Masayuki has another experience and visits the research center.
Michio is now able to cross into the Unseen World. Makoto is still in Kumada. Takahito, concerned for Miyako, delved into the concept of the Lord of One Word. Tarou begins to suspect that Miyako may be the reincarnation of his dead sister.
Tarou reflects upon what he said to Miyako. Makoto remains in Kumada. The investigation into the DBI continues with Suzuki reporting some new findings to the Chief. It seems there may be some connection between the DBI and a rash of kidnappings 11 years earlier.
Makoto rescues his mother when the house is destroyed by a fire. She is taken to the hospital, but does not seem to be quite herself. Meanwhile, Takahito has a fall and is also taken to the hospital where he is comatose. The incidents seem unrelated, but they share a mysterious coincidence that does not seem all that coincidental.
Dr. Reika and Dr. Atsushi discuss his MRI scan and the possibility of Lewy Body Dementia. Suzuki begins to investigate Reika's and Makoto's mother. When Miyako is chosen to lead the Oogami group, Tarou crosses into the Unseen World to find Takahito.
Takahito finally wakes from his coma, but may be unable to help Miyako. Makoto stays with Tarou's family and learns that their fathers were close friends.
The town prepares for a typhoon and the possible destruction it may cause. Tarou, Masayuki, Makoto, and Michio seem to be the only ones capable of rescuing Miyako from what the Oogami group has planned.