I Wanted to Be a Shop Manager, But Became a Swordsman

Mitsunari transmigrated to Tokyo, becoming an ordinary high school student.His mother left home, leaving behind two hundred thousand yen, a martial arts equipment store, and a cute little sister.The yen turned from paper bills into coins, the martial arts equipment store was on the verge of bankruptcy, and his sister was clamoring to drop out of school.Helplessly, Mitsunari could only roll up his sleeves and become the shop manager.The goal was to become the coolest shop manager in Tokyo!......Many years later, Mitsunari was bestowed with the title of "Reiwa Sword Saint", famous throughout Japan.But seriously, how did I, a bamboo sword seller, become a Sword Saint?There must be something wrong with this, right?!