Simple, although he is a simple second-generation ancestor. One day, an accident happened quietly, and things were not simple at all... Suddenly he found out that he had been exchanged with his arch-enemy, but it would have been better if he was a brother. But she was a well-known lady in the circle, the future heir of the family, and he had been someone else's child since he was a child. And he was known to enjoy himself. With his brother to support him, he knew that he was unreliable... The house leaked and it rained all night, and he discovered that there was a system between them! It turns out that the exchange between them originated from the system, so the two were forced to complete the system tasks diligently to make up for the so-called "regret"...