All Japanese TV serials have to start with a transfer student. Demon Ward is set in a hospital so it starts with a new nurse Ogami joining a hospital. Nurse Ogami is very timid but she has a few years of experience as a nurse. She has also spent a few months in a pyschiatric ward as a patient. She desperately hopes her mental illness will not return.
Sometime after the nurse starts working, she and others at the hospital begin to encounter some ghosts.

Instead of an abandoned school building, this horror drama has an abandoned hospital building. A lot of documents are still stored there and the head nurse is afraid to go there during the night shift. She sends other nurses like Ogami to go instead.

To make matters worse, some patients act uncomfortable around the new nurse.

… particularly after her face shows up in odd places. The nurse is left wondering why she is being targeted in this sinister way.

She and another doctor have nightmares of a demon wearing a white kimono. There are apparitions of patients with serious body trauma and blood loss. There are demons hiding in toilets. Poltergeist activity and whatnot.

The suspense is amplified by the fact that each episode runs for only 22 minutes. This includes the title credits. Some scenes are repeated in a subsequent episode to provide the backstory, making you go, "Aah!!!".
This is a good TV drama that provides a lot of scares and suspense. The ending is perfect, which has been difficult even for the best horror filmmakers. All in all, this is good entertainment.
There is another Japanese TV drama that you can watch if you wish to learn more about Japanese horror themes. It is a parody called The Great Horror Family.
Recommended age rating: 14+