Decades ago, the manor was attacked by Servants of an unknown Master. Their only goal seemed to be the death of everyone in the territory. There were no survivors. Our main character Master was saved from death by his uncle, who raised him.
Since there is no one left alive to explain why he had to grow up as an orphan, he returns home with his only Servant - his childhood friend - seeking to rebuild his family estate and take revenge on the one who tried to burn it to the ground. And hopefully build a harem of cute maids along the way~