The pinnacle of modern civilization known as Japan is now long forgotten. Ravaged by civil war and technological collapse, Japan has regressed into a post-Meiji era society and is now divided into three imperial territories known as Yamato, Buo, and Seii.

However, Aoteru Misumi, a 15-year-old literature enthusiast, dreams to bring back the culture and technology that once made the pride of his country. Although unwilling to turn his theoretical knowledge into concrete action at first, a tragic turn of events drives Aoteru to head to Osaka in hopes of enlisting in the army and eventually uniting the country under his own banner.

Osaka—once one of the three jewels of Kansai—has become a crime-ridden city where Aoteru almost loses his life. Luckily, he encounters a fellow ambitious young man named Yoshitsune Asama who pursues the same dream. With Aoteru's strategic prowess and Yoshitsune's masterful swordsmanship, the two now embark on a journey to restore the former glory of Japan.