Teito Monogatari Gaiden (1995)

Original title: 帝都物語外伝

In 1995, a mental hospital is erected near the Japanese Ministry of Finance, located adjacent to the grave of Taira no Masakado. A young male nurse by the name of Jin’ya Yanase is obsessed with the legend of Taira no Masakado and more importantly, the spirit of his evil subordinate Yasunori Kato. Slowly, he becomes possessed by Kato's spirit, who wants to use him as a new host to revive in the modern world. Keiko Tatsumiya (the heroine of the original story), is an old woman living homeless on the streets of Tokyo. When she senses the presence of Yasunori Kato, she must regain her resolve to face the demon-god and vanquish his spirit once and for all.