Toa is reincarnated as the second son of an aristocratic family, while retaining his memories of life on Earth. He aims to live a leisurely life in another world, but is exiled to a remote fortress at a young age due to his lack of talent for swordsmanship or magic. Ten years later, he is called back after his father's death, only to be disowned by his older brother Gras, who has inherited the family business.

Undeterred by such harsh circumstances, Toa uses the power and knowledge he gained at the remote fortress to become an adventurer. However, after helping a girl named Nikka whom he meets during the guild entrance exam, he becomes embroiled in an incident that shakes the royal capital――!?