Carlo, an alchemist in the Mario Kingdom, is a capable man with great things expected of him.

However, when he is persecuted by the Princess Knight Alessandra for creating a creature of taboo, the Genome, he is run out of the country.

Several years later...

Thanks to the work of Alessandra's little sister Laura, he has a chance encounter with Alessandra. His plan is to use the princess knight as a nursery for his Genome and have her bear their children...

[from DLSite English]