JUX-284 Mother-in-law's Atonement - Incestuous relationship to atone for her son - Yui Oba

Yui, a widow, loses her husband in an accident soon after getting married and ends up living with her stepchild S**. - S** spends his time supporting his heartbroken mother-in-law, and in the middle of the night, he is unable to suppress the disgust that is welling up in Yui as she comforts him in front of the deceased's photograph... - Out of loneliness, Yui accepted his desire, and their twisted newlywed life began. - However, there was no way that such a life would go well and the end came suddenly. - One day, S** finds a letter addressed to Yui from his father's Buddhist altar. - What was written there...