One Piece is a beloved and long-running manga and anime series with thrilling storylines, memorable characters, and epic battles. At the center of this adventure-filled world is the charismatic protagonist, Monkey D. Luffy. One of Luffy's most iconic abilities is his Gear Fourth transformation, a powerful and visually striking technique that has left an indelible mark on the anime series. Gear Fourth, also known as Boundman, is Luffy's awe-inspiring form that grants him immense strength and speed, allowing him to take on his opponents with ease. This transformation, made possible by Luffy's rubber-like body and mastery of Haki, is a testament to his relentless pursuit of power and growth. A fanart One Piece anime progress bar for YouTube with Monkey D. Luffy Gear Fourth.