In 2010, during a stay in San Diego, California, Japanese student Haruka Yamano (Noriko Aoyama) is involved in a car accident that breaks both of her legs and cutting her trip short and she returns to her home in Tokyo, Japan. Shortly after her return, Shigeyuki (Kazuyoshi Tsumura), her father, leaves for a business trip abroad in Singapore, leaving her with her 19-year-old, younger brother Koichi (Aoi Nakamura).
Haruka discovers one morning that her wheelchair has moved despite the wheels being locked. After discovering the wheelchair has moved despite the windows being locked, Koichi suspects it to be a paranormal force. Koichi places a mound of salt in Haruka's room and films it without her knowledge. The next morning the salt is scattered and while reviewing the film they see the salt scatter with no visible means. Koichi begins to investigate further by filming Haruka sleep though she disapproves and eventually insists he grow up and stop believing in supernatural nonsense until a drinking glass breaks during dinner.
Reluctantly, Haruka lets Koichi film her during the night again, this time recording the curtain beside her bed moving and the blanket being pulled from the bed. Koichi's friend Jun Nagoshi (Kōsuke Kujirai) visits the next day with his girlfriend Mai Yaguchi (Maaya Morinaga) and her friend Misuzu Kure (Ayako Yoshitani). Misuzu remarks feeling a strange presence at the Yamanos' house and Koichi asks if she can investigate the demon haunting Haruka. After examining Haruka's room, Misuzu claims she has never felt a presence like this before and suddenly plugs her ears, screaming and foaming at the mouth, and quickly leaves. Through the internet Koichi finds and contacts someone to perform a purification ceremony. That night while doing homework Koichi is alerted to the presence of someone in the house, on the first floor. He goes to investigate and finds ceiling lamps flickering and very loud music blaring from the radio in the living room.
Koichi and Haruka invite a Shinto priest over to their house to perform a purification ceremony. The priest tells them the presence has likely settled down and assures the two that they have nothing to fear. The following nights progresses with no incidents. After a couple of days, Shigeyuki returns home from his business trip. On night 12, Haruka's wheelchair moves towards the camera and cuts it off. Haruka and Koichi review the footage and realize that the presence has not gone. Koichi tries contacting the Shinto priest from the purification ceremony, but is told the priest died of a heart attack after leaving them. The next night, the events worsen when Haruka is violently dragged out of bed by her hair by a force she believes to be under her bed. The two siblings consider leaving the house. Haruka tries to contact Shigeyuki but he is not answering his cellphone.
Haruka then recalls Katie, a woman involved in the same car accident that cut her trip short, and after searching her name on the Internet, believes that the demon that had possessed her is now targeting Haruka. She reveals to Koichi that she experienced similar strange phenomena while recuperating in the hospital in America. Haruka tells Koichi to escape without her if the demon attacks them both. In the night, he hears her screaming and finds her in the yard in her wheelchair. Haruka claims that the demon is tormenting her from behind and reveals a strange bite mark on her arm before losing consciousness. Koichi watches Haruka for the rest of the night and, in the morning, places a crucifix in her hand. After he leaves the room, Haruka drops the crucifix and it moves along the floor before combusting and several windows break spontaneously in the room. Meanwhile, Haruka remains asleep throughout the commotion. Koichi brings her breakfast upstairs and upon discovering the scorched crucifix and broken glass everywhere, breaks down in tears as Haruka sleeps on.
On night 15, Haruka wakes up at 1 AM, stumbles to Koichi's room, and stands by his bedside staring at him for two hours while he is asleep. Around 3 AM, she walks downstairs and wakes Koichi with a scream. Alarmed, Koichi runs to the living room where he discovers Shigeyuki's corpse in one of the closets. A possessed Haruka appears and knocks the camera from his hand and then violently throws Koichi at the camera in his room and slowly approaches. Koichi escapes and boards a taxi outside of his house. As the taxi drives away, Haruka suddenly appears in front of it and it strikes into her before slamming into a wall. The crash kills the driver while Koichi survives. The screen fades to black.
Later, Koichi goes to a funeral home to pay his respects to his sister who is believed to have died in the crash. When Koichi removes the sheet he is shocked to see that it is in fact not the body of his sister, but the taxi driver instead. Koichi is suddenly dragged into the darkness screaming and the camera cuts to black for about 15 seconds. When the camera begins running again, Haruka is seen staring at it, the demon sound from the original Paranormal Activity is heard as the scene cuts out.
An epilogue text states that Koichi was found dead, Shigeyuki's body was discovered in the house later and Haruka's whereabouts remain unknown. Some versions don't have the text in the end.Aoi Nakamura as Koichi Yamano
Noriko Aoyama as Haruka Yamano
Kazuyoshi Tsumura as Shigeyuki Yamano
Kōsuke Kujirai as Jun Nagoshi
Maaya Morinaga as Mai Yaguchi
Ayako Yoshitani as Misuzu Kure
Tōze Yamada as the Exorcist
Shinji Matsubayashi as the Exorcist's Assistant
Jan Franco Ognabenni as the Judge
Paranormal Activity 2: Tokyo Night was released on November 20, 2010 in Japan.
Paranormal Activity 2: Tokyo Night was released onto rental DVD and Blu-ray on March 4, 2011. It was then released for home entertainment on April 5, 2011.