How many movies have Arashi and Masahiko Kawahara collaborated on?

They have worked on 4 movies together! Their first movie together was Pika*nchi Life Is Hard Dakedo Happy (2002) while their highest rated movie together was Pika**nchi Life Is Hard Dakara Happy (2004). They have not worked together since Pikanchi Half: Life is Hard Tabun Happy (2014). They are most known for their drama films together.