Lu En awakens in the dangerous world of One Piece as the grandson of the Marine Hero Monkey D. Garp and the son of the Revolutionary Army leader Dragon. Facing a future where his younger brother Luffy is destined for chaos, Lu En resolves to forge his own path of absolute strength.

Transmigrated with a mysterious 'Ghost Back System,' he endures hellish physical training under Garp's brutal tutelage. The system rewards his relentless push-ups and endurance with exponential cultivation multipliers, turning basic exercises into god-like power gains. Starting with a tenfold boost, Lu En quickly unlocks a hundredfold amplification, allowing him to achieve in days what takes others a lifetime.

As his 'Ghost Back'—a legendary physique of terrifying muscle—begins to manifest, Lu En sets his sights on mastering all three types of Haki before his fourth birthday. In a world of pirates and marines, this young prodigy aims to become an unstoppable force, ready to shake the very foundations of the seas.