There was a young man in the Seto Inland Sea, in the Shiwaku Islands. His name is Douma Nada Taro. Many enemies appear in front of him who set sail to unify the Seto Inland Sea. Nadataro and his friends defeat their enemies and increase their number of allies with their military strength, sparrow power, and most of all, their charm as humans. After a fierce battle, the Etajima army, the largest force, appears after defeating the Innoshima army!!