My Quadruplet Brides~ I choose all of you 1.0 by AKABEiSOFT3 - Adult Sex Game

Masamune, the protagonist, spent much of his life alone. His parents were often away on business trips, and so he often yearned for the warmth and love of a normal family. When he was younger, both his parents had to leave at the same time for business, and he was sent to stay with his relatives.

It was then that he met the four girls who would become his life partners.