La blue girl 3: lady ninja (1996)

Part 3 of this live action Hentai series begins with tasty ninja babe Yaku contacting her equally sexy cousins, Seia, Fuka and Maki, for help in her battle against the Shikima sex demons. After all three of her cousins have arrived, and wounded Bido warrior Miko has been nursed back to health (Fuka applies a special potion to the patient and uses her naked body to thoroughly rub it in), the girls make one last bid to defeat their evil, tentacled enemies.