Shiki Jôkyô Nikki: Chôinran [色情狂日記 超いんらん]

Ippei, a private detective, was suddenly involved in a strange incident at the request of Nao. He was guided by Nao and went on a trip to the hot spring town with his assistant, Santa, but when Nao's best friend and landlady Harumi had a seizure for some reason, he was in agony in search of a man.