The Ninja, whose real name is Ninja Nedokuro (ニンジャ 根怒骷髏), is a mysterious and skilled Choujin (superhuman) fighter in the anime and manga series 'Kinnikuman.' He is a member of the feared Akuma Choujin group, known as the Devil Knights, and is recognized for his stealth, ninja techniques, and ruthlessness in the ring. Serving as both an antagonist and a notable rival, The Ninja stands out for his dedication to the art of ninjutsu and his complex sense of honor amidst the chaos of the wrestling world.