How many movies have Naoyuki Tomomatsu and Yûya Takayama collaborated on?

They have worked on 9 movies together! Their first movie together was High School Teacher, But I'm a Student... (2002) while their highest rated movie together was Rape Zombie: Lust of the Dead 5 (2014). They have not worked together since Love Zombie: Romance of the Dead (2015). They are most known for their horror films together.