If you loved Detective Conan: Private Eye in the Distant Sea, try Fist of the North Star: The Legend of Kenshiro
A bridge between a film you've already seen and one most people haven't. Fist of the North Star: The Legend of Kenshiro has roughly 3.0× fewer votes than Detective Conan: Private Eye in the Distant Sea — 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.

Detective Conan: Private Eye in the Distant Sea

Fist of the North Star: The Legend of Kenshiro
What they share
Both films are directed by Kobun Shizuno, and they both carry the raw mood tag, and they sit in Action / Animation / Drama territory. If that's the register that drew you to Detective Conan: Private Eye in the Distant Sea, the second film will land in a comparable space — through a different lens.
What Fist of the North Star: The Legend of Kenshiro is
You languish in desert captivity after a brutal fight. Your martial gifts could buy freedom. But the slave camp holds innocents. Then raiders appear. Shizuno's camera fixates on sinew and scar. A brutal origin story is reborn.