If you loved One Piece "3D2Y": Overcome Ace's Death! Luffy's Vow to his Friends, try One Piece Episode of Nami: Tears of a Navigator and the Bonds of Friends
A bridge between a film you've already seen and one most people haven't. One Piece Episode of Nami: Tears of a Navigator and the Bonds of Friends has roughly 3.7× fewer votes than One Piece "3D2Y": Overcome Ace's Death! Luffy's Vow to his Friends — 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.

One Piece "3D2Y": Overcome Ace's Death! Luffy's Vow to his Friends

One Piece Episode of Nami: Tears of a Navigator and the Bonds of Friends
What they share
Theyboth carry the cozy, playful mood tags, and they sit in Action / Adventure / Animation / Comedy / Fantasy territory. If that's the register that drew you to One Piece "3D2Y": Overcome Ace's Death! Luffy's Vow to his Friends, the second film will land in a comparable space — through a different lens.
What One Piece Episode of Nami: Tears of a Navigator and the Bonds of Friends is
Nami’s personal saga gets the localized spotlight, which, predictably, involves storm clouds and stolen ships. The crew pursues her to her flooded hometown where Arlong’s reign drowns the joy out of maritime maps. Loyalty, like tides, occasionally gets pulled under too.