Whore Angels (2000)

Original title: ピンサロ病院 3　ノーパン診察室

Komasa is a female drifter works at a pink salon-- a shop specializing in fellatio-- called "Hot Lips". On the way to work one day she rescues a female stranger from an attack by an evil-looking man. Monroe, the stranger, kisses Komasa whose wounds received during the fight are then healed. Monroe takes up employment at the pink salon, where it is learned that her supernatural powers cure every man on whom she performs fellatio of all ailments. Monroe's miraculous healing powers lead to the shop's increased popularity. Eventually it is discovered that Monroe is actually an angel and that the man Komasa rescued her from is the devil, bent on subjugating the living. Komasa vows to fight to save Monroe and life on earth.