One Piece: Gyojin Tou-hen

Luffy and his crew were on their journey to find the one piece and for that, they crossed the red line. During their journey, they have to stop on a Fish Men Island. This island is located across the Redline and is ruled by fishmen and Mermaids. The human there was trapped by the Hody Jones. Jones is a chef of Fishmen and very radical that torture people. Luffy decided to help them and for that, he battled and won and was able to bring peace to that island.