How many movies have Rikio Ichikawa and Yukihiko Yamaguchi collaborated on?

They have worked on 4 movies together! Their first movie together was Kaidan Shin Mimibukuro Nagurikomi! Gekijō-ban Kantō-hen (2011) while their highest rated movie together was Kaidan Shin Mimibukuro Nagurikomi! Gekijō-ban Makai-hen Zenpen (2013). They have not worked together since Kaidan Shin Mimibukuro Nagurikomi! Gekijō-ban Makai-hen Kōhen (2013). They are most known for their horror films together.