Gear Second is one of Monkey D. Luffy's signature techniques in One Piece, first used when he needed far greater speed and strength against a much stronger opponent. The activation sound, with its heartbeat and steam, quickly became shorthand for a power-up in anime edits, AMVs and short-form videos, where creators use it to signal that a character is about to go all out. Its popularity has lasted because the sound is short, dramatic and immediately understood by anime fans, even without any dialogue or context.