[One Piece × X-Men] Tension between humans and mutants only grows by the day.... From both sides there are those who cause trouble, souring relationships. War seems highly possible. But as all this is happening a Joyful Boy makes his presence known as THE FUTURE KING OF THE MUTANTS! Join Monkey D. Luffy as he adventures across the world, gaining allies and enemies as he rises to the throne and becomes a modern day king for the next stage of human evolution.