The Kumagawa Hospital which is located in the outskirts of town. Ogami Runa joined as a nursing staff 2 weeks ago. One night, with the lights all turned low, her fellow colleague, Suzuki Ayako is terrified out of her wits when a woman dressed in a school uniform (sailor) with blood dripping all over her, appears before her.

A few days later, Runa's childhood friend, Sakai Manami who works at a movie production company, calls her out for a meet-up. Ever since she was a child, when she saw the ghost of her dead schoolmate, Runa realises that she could sense and see the ghosts around her. Bullied by her other classmates, Manami is the only one who had befriended her.

Due to her ability, Runa always tries to ignore talks of ghosts sightings by other nurses and patients. Amidst all these, the medical intern Kumagawa Asahi, whose father owns the hospital, has a strange fascination with the mysterious old hospital wing's top floor.

One night, Runa goes to the old hospital wing to fetch some supplies, and she hears a voice calling out her name. Entranced, Runa follows the sound and goes up to the top floor. She bumps into the wall at the end of the corridor, and the sound seems to come from within. Perplexed, Runa stands there contemplating the wall, when all of a sudden, a door appears before her eyes...