One Piece Episode 991

Episode 991 adapts chapters 983–984.

Enemy or Friend? Luffy and Yamato! · Wano arc

Anime

Episode 991Enemy or Friend? Luffy and Yamato!

Manga chapters

Chapter 983
Chapter 984

One Pace

ThunderCovers chapters 982–983
My BibleCovers chapters 984–985

The details

Episode 991 adapts chapters 983–984. Adapting several chapters into one episode is why the anime slowly gains on the manga in raw numbers even while falling further behind in story.