第644集 - 路飞的终极考验！争夺海贼王之战的战斗

Episode 644
Luffy's Ultimate Test! The Battle to Become the King of Pirates
Japanese: ルフィの究極の試練！海賊王になるための戦い
Rufi no Kyūkyoku no Shiren! Kaizoku-Ō ni Naru Tame no Tatakai

The Straw Hat Pirates, having faced their greatest challenge yet, finally uncover the truth behind the treasure and the lost civilization that once ruled the Grand Line. With the power to change the world now in their hands, the crew prepares to make a choice that will determine the fate of the Grand Line.