A divided 16th century Japan, a time known as the Warring States period, gave rise to samurai leaders central to history. Oda Nobunaga is one example. He is a legacy of innovation. He revolutionized tactics with the introduction of firearms, enacted economic reforms, and his design for Azuchi Castle would forever change how Japanese castles were constructed. Why does he remain such a popular figure? Modern-day Japanese leaders and admirers share what they've learned from this legendary samurai.