Ghost Hunt

The decrepit building was condemned long ago, but every time the owners try to tear it down, "accidents" start to happen-people get hurt, sometimes even killed. Mai Taniyama and her classmates have heard the rumors that the creepy old high school is haunted-possibly by ghosts from the Second World War. So one rainy day they gather at the told school to tell ghost stories, hoping to attract one of the suspected spirits. No ghosts materialize, but Mai and her friends do meet Kazuya Shibuya, the handsome young owner of Shibuya Psychic Research, who's been hired to investigate paranormal activity at the school. Also at the scene are an exorcist, a Buddhist monk, a woman who can speak with the dead, and an outspoken Shinto priestess. Surely one of them will have the talents to solve this mystery! (Source: Del Rey)

The two books are a continuation of the Evil Spirit Series (Akuryou), but in a different setting.

Midori's mother has finally acquired her dream home, but it isn't long before supernatural phenomenas disrupt the peace of the family. And if unexplained electricity failures, strange phone calls, and the eerie presence of spirits weren't enough, finding unexplainable blood in the bathroom becomes the last straw. Mai and Shibuya Psychic Research are brought in to investigate, but what horrors will they find in the 'dream' home that turns out to be nothing but a nightmare? Akumu no Sumu Ie - Ghost Hunt is based on a sequel novel of the original set several months in the future from the original Ghost Hunt. It was published in 1994 and was only two volumes long. (Source: Wonderland After Hours)