Maruhi sennyû: Gyaku soap tengoku

A university assistant professor spends his days researching. A hidden camera is installed at a reverse soap shop run by a friend of his, and he studies techniques by observing the reactions of female customers...

Cast: Koyuki Fuji, Jun Yahagi, Kaori Kuwabara, Kanichi Hiraga, Masahiro Yoshida, Ryou Kurihara