After dying in a workplace accident, Yoshida is given a second chance at life in a world of swords and magic. Due to a mishap during his reincarnation, he's sent to another world with an angel who caused the error, as his twin sister. Years later, Yoshida trains under his sister, honing his magical abilities. His sister, having decided to enjoy this new life, plans to live comfortably off her brother's success. Will Yoshida become an adventurer, or will he take over the family inn? His second life, with his parasitic sister, begins!