How many movies have Akio Otsuka and Kazuhiro Wakabayashi collaborated on?

They have worked on 6 movies together! Their first movie together was Ghost in the Shell (1995) while their highest rated movie together was Howl's Moving Castle (2004). They have not worked together since Ghost in the Shell: Stand Alone Complex - Solid State Society (2006). They are most known for their animation films together.