One Piece (1999): 3D2Y: Overcome Ace’s Death! Luffy’s Vow to his Friends

Luffy is currently in Rusukaina training to get stronger to take on the New World. However, the training is interrupted when Hancock's sisters, Marigold and Sandersonia, are kidnapped by Byrnndi World, a pirate who was locked away on Level 6 of Impel Down.