New wife, new wife, new wife? I AM THE WIFE!!! by Lilith Soft - Adult Sex Game

Ichijo heir to an old dynasty from a wealthy family, lives alone. His future is big business, which he should soon take over. Gifted and talented from birth, brought up in abundance and comfort. After graduating from high school, he moves into a dilapidated house, inherited from his grandmother, where he wants to create a setting for writing a novel. In his literary outpourings, he is assisted by three girls, to one degree or another connected with this family.