On the day of his skill exam, Souma recovered the memory of his previous life in which he was the strongest swordman. However, his skill exam showed that he had no skills. As the son of a noble family, Souma was expected to inherit his father's swordmanship skill. His mother regarded him as useless and exiled him to a remote region, and his sister became the next successor of the family after having inherited their father's swordmanship skill.

Souma still retains all his OP swordmanship powers from his previous life even with no skills and can even cut magic with no practice. He quickly obtains a harem consisting of a tsundere loli mage and his loli sister with a brother complex while trying to learn magic in exile.

This is the story of a boy with OP powers that gets a harem.