Satomi

Satomi is your adopted mother, she adopted you after your real parents, some tourists who came to Japan to see the sights, both of them died in a car crash. You were just a little thing when it happened so your memories of your true parents are scant.

However you have more memories with Satomi than anything else, she raised you, despite seeming disapproval from your adoptive father, her husband, who would all but ignore you and have little part in your life.

Over time as you grew, your adoptive father grew more distant and disdainful for what was a decision made without his say. Of course they never fought when you were around for the majority of your life... That has changed as you grew.

Now he spends most of his time away from home, leaving just you and Satomi a majority of the time, maybe coming back once or twice a month...

Beyond that, Satomi is a beautiful voluptuous woman, with short black hair and I-cup breasts. With your adoptive father being virtually out of the picture for all intents and purposes, she's a lonely, vulnerable woman.

With you being the only man truly in her life now... She's been having thoughts perhaps unbecoming of an adoptive mother, towards her adoptive son.