If you loved Naruto Shippuden the Movie: The Will of Fire, try Naruto: The Lost Story - Mission: Protect the Waterfall Village!
A bridge between a film you've already seen and one most people haven't. Naruto: The Lost Story - Mission: Protect the Waterfall Village! has roughly 3.2× fewer votes than Naruto Shippuden the Movie: The Will of Fire — it's a deeper cut, not a mainstream recommendation. Here's what they share, and what the second one does that the first one doesn't.

Naruto Shippuden the Movie: The Will of Fire

Naruto: The Lost Story - Mission: Protect the Waterfall Village!
What they share
Both films are directed by Masahiko Murata, and they both carry the cozy, cult, foreign gem mood tags, and they sit in Action / Adventure / Animation territory. If that's the register that drew you to Naruto Shippuden the Movie: The Will of Fire, the second film will land in a comparable space — through a different lens.
What Naruto: The Lost Story - Mission: Protect the Waterfall Village! is
You're a ninja, tracking thieves who've raided sacred springs. But a rival squad complicates your mission. Date's direction keeps the focus tight. What remains is a question: can loyalty overcome duty?