How many movies have Kazuhiko Inoue and Kazuhiko Seki collaborated on?

They have worked on 4 movies together! Their first movie together was Seito Shokun! Kokoro ni Midori no Neckerchief o (1986) while their highest rated movie together was Natsume's Book of Friends: Ephemeral Bond (2018). They have not worked together since Natsume's Book of Friends: The Waking Rock and the Strange Visitor (2021). They are most known for their animation films together.