Separated as children and unaware they're siblings, a brother and sister struggle to reunite, reclaim their birthright, and save the world.

After being left for dead, Denji turns into a devil-human hybrid with chainsaw powers, and gets recruited into a governmental devil hunting agency.

Seeking a rematch, the Foxy Pirates trick the Straw Hats into landing on an island. But it's all part of a larger scheme to destroy them!