Oda Nobunaga revolutionized Japan with his military, cultural, and political innovations. He divided his elite bodyguards into Akahoro-shū (red-cloaked) and Kurohoro-shū (black-cloaked) groups, emphasizing discipline and intelligence warfare. Nobunaga banned looting, enforced strict rules like Issen-giri, and maintained order, earning public support. He introduced area armies for multi-front campaigns and pioneered naval innovations with iron-armored ships.

A patron of the arts, Nobunaga elevated the tea ceremony as a samurai ritual and promoted sumo tournaments to display authority and martial values. He popularized razor blades for samurai grooming and employed Yasuke, the first known African in Japan. Nobunaga's vision laid the foundation for Japan's unification and cultural transformation.