For over seven hundred episodes, One Piece fans watched Monkey D. Luffy brute-force his way through impossible odds. From the clanking joints of Gear Second to the bloated inflation of Gear Third, his power-ups were desperate, visceral, and bloody. But in the pantheon of the series’ most shocking transformations, none redefined the physics of battle quite like Gear Fourth: Boundman . The moment Luffy unveils this form occurs in Episode 726 , titled “Gear Fourth! The Phenomenal Boundman.” To dismiss this as simply a “power-up episode” is to miss the brilliant narrative subversion Eiichiro Oda engineered. In this single episode, Luffy doesn’t just get stronger; he abandons the shonen trope of the plucky underdog and embraces the terrifying role of a calculated emperor. The Collapse of the Rubber Logic Prior to Episode 726, Luffy’s fighting style was defined by momentum and recoil. Gear Second was a sprint; Gear Third was a sledgehammer. Gear Fourth, however, is a singularity. The episode begins with Luffy biting into his own arm—a grotesque act of self-cannibalism rarely seen in the series. He inflates not just his bones (Gear Third) but his muscles , compressing the air into his body cavity. The visual design is jarring: Luffy becomes a titanic, bouncing behemoth with steam rolling off his shoulders like a furnace.
In conclusion, Episode 726 is not just “the episode where Luffy uses Gear Fourth.” It is the episode where One Piece pivots from adventure to warfare. Gear Fourth represents the death of the underdog. When Luffy screams “ Gomu Gomu no Kong Gun ” and the screen turns white, he is no longer the kid from Foosha Village. He is the warlord who will tear the sky apart. For fans, the episode remains iconic not because of the power level, but because of the terrifying realization that Luffy is finally willing to become a monster to protect his crew. And that bounce? That’s just the rhythm of a new Pirate King warming up. which episode does luffy use gear 4
This is the essay’s central irony. In Episode 726, Luffy becomes a god, but a god with a severe battery life. He defeats Doflamingo not by overpowering him in a single punch, but by outlasting him within a self-destructive timer. The episode teaches viewers a harsh lesson about the New World: You cannot win unless you are willing to break the very mechanics of your body. Why does the specific episode number matter? Because Episode 726 airs directly after the flashback of Corazon and Law—a story about sacrifice. By juxtaposing Law’s tragic past with Luffy’s monstrous transformation, the show argues that power in the New World is a form of sacrifice. Luffy loses his boyish silhouette. His eyes become rimmed with the intense glare of Conqueror’s Haki. He stops smiling during the fight and starts grinning maniacally. For over seven hundred episodes, One Piece fans
The essay’s thesis lies in this contrast. In Episode 726, the animation style shifts from fluid motion to stop-motion impact. When Luffy uses against Donquixote Doflamingo, the screen doesn’t just shake; the sound design cuts out. We see the fist connect, the air pressure explode, and the city of Dressrosa split in half. Oda uses this moment to tell the audience that we are no longer watching a pirate who survives by luck. We are watching a Yonko-level threat in training. The Price of the Mask What makes Episode 726 critically interesting is the subversion of “effortless power.” Most shonen transformations (Super Saiyan, Kurama Mode) grant a serene, golden aura. Gear Fourth is ugly. Luffy bounces uncontrollably. He has to use Haki to keep his rubber body from tearing itself apart. The episode cleverly inserts a ticking clock: because the form consumes so much Haki, Luffy cannot move for ten minutes after it deactivates. But in the pantheon of the series’ most