Chapter 0 is called “Strong World“. It is a special chapter released with Chapter 565. It introduces the events 20–25 years before Monkey D. Luffy began his adventure, and the story of Shiki for the 10th One Piece Film: Strong World.
Color Spread: Straw Hats (minus Nami) dressed in formal black clothes, wielding various guns and ready for action.
You can also watch the One Piece Strong World: Episode 0, which is based on this chapter.
-Shiki mentions that Roger had located an Ancient Weapon.
-Shiki’s head injury comes from his fight against Roger.
-Shiki was sentenced to Impel Down, but escaped by cutting off his feet.
-Shiki plots a twenty year plan.
-Those who saw the film received the volume 0 containing this chapter for free.
-An OVA (Original Video Animation) was made based on Chapter 0.
-When Impel Down’s entrance is displayed, wave and wind movements can be seen, which shouldn’t be happening – as it is located in the Calm Belt, a zone without wind and sea currents.
-This is the first and only chapter so far to have a double tankobon release, in both Volume 0 and fifth databook One Piece Blue Deep.