Gear Fourth is a transformation used by Monkey D. Luffy in Eiichiro Oda's One Piece, first unleashed during the Dressrosa arc against Donquixote Doflamingo when Luffy needed far greater speed and power. The form inflates his muscles with compressed air, giving him the springy, bouncing Boundman style that became instantly recognisable to fans. Clips of the power-up spread through anime edits, AMVs and short-form videos, where the distinctive swelling sound became shorthand for a character going all out. It remains popular because it marks a clear turning point in a fight.
About this sound
The Gear 4th sound effect from One Piece captures Monkey D. Luffy powering up into his powerful Boundman form for anime edits and reaction videos.
This clip captures the dramatic audio moment when Monkey D. Luffy activates Gear Fourth in One Piece, a transformation marked by a deep, swelling burst of energy, heavy impact sounds and a powerful, echoing roar that signals a sudden jump in strength. The sound builds tension as air compresses and muscles inflate, then releases it in a punchy, larger-than-life hit that feels both cartoonish and intimidating. For viewers, it instantly reads as a power-up: the hero is no longer holding back, the fight is about to escalate, and something huge is coming next.
