Students, including Aoi Nishino, take part in class and sports activity at a prestigious high school. Aoi Nishino is a member of the school's archery club. He practices archery studiously and doesn't socialize much with the other students. His childhood friend Haruka Seno is also a member of the archery club, but she worries about Aoi Nishino. One day, thunder strikes the school grounds. After that, the ordinary lives of the students changes drastically. Many samurai descend on the school grounds. It appears that the entire school has traveled back in time to the Sengoku period. Making things worse, they realize that they are in the time right before the Battle of Okehazama takes place.

Before Tokugawa Yoshimune, known as the "Ravage Shogun", was the lord of the Kishu domain, before he became the shogun! Yoshimune hides his identity and begins an investigation in the city of Edo in order to find out who he really is. As he grows up, he ends up throwing himself into a turmoil involving the shogunate... This is an entertainment historical drama in which a young 21-year-old named Yoshimune solves the problems of the common people in the city and goes around dealing with merchants and powerful people plotting evil deeds.