How many movies have Naoki Oka and Yoshikazu Katō collaborated on?

They have worked on 5 movies together! Their first movie together was Molester and Peeping in the Nunnery Toilet (2000) while their highest rated movie together was Aniki to ore (2003). They have not worked together since Cabin Attendant lust flight hip-shaking erotic air currents (2008).