Orgasms: Bath House Secret Techniques (1974)

Yuko (Masumi Jun) is the number one, top-grossing prostitute operating at Paradise Bath House. She's a smart girl, a college graduate. Kaneyo, her second best, is not happy about this. After a few confrontations between the two whores, they have an impressive fight in the soap suds. A new girl arrives, Kinuko (Yuri Yamashina) who is instantly popular with all the gents due to her soapy-hand technique. The calm days at Paradise bath House seem to be back, only their male customers are being robbed, with evidence falling either on Yuko or Kaneyo.