Toaru Shuju no Koi no Hanashi

Five years ago, Yuno suddenly left his job as a servant, because he loved his master Masaki too much. Now he lives quietly with his young son, Wakana. One day, Masaki shows up, having grown up into a handsome young man. Masaki's goal is to bring back Wakana, who is also his late sister's son. Masaki offers them a one-month grace period, and Masaki will live with them during that time... Taking care of them like the past, all three of them sleeping together in one bed, the happy times rekindles the love that Yuno thought he had thrown away... The love story of a former servant with a child and the reunion with his master.

(Source: Hanaoto, translated)