Targeted mother's anus

Kiriko, who grew up in an orphanage, was taken in by the Hiratsuka family, a large landowner, as a live-in housekeeper 24 years ago. Soon after, the head of the family, Tomio, forced her to do a service other than that of a housekeeper, and although she tried to run away many times, the young Kiriko had nowhere to go and had no choice but to serve like a slave. The person who supported her was Tomio's son, Yutaka. Yutaka has loved Yutaka ever since she was born, and she was most happy about it, but there was a secret between them...