HZGD-112 Wife raped in front of son Yuu Kawakami

The stepmother 'Yu' struggles with the awkward distance between herself and her husband's child from his previous marriage. One day, a shady man suddenly appears and informs her that her son has hit an old woman with his bicycle and fled the scene. He demands a large sum of money and says to make up the difference with her body. From that day on, she is raped every day... What action does her son take after witnessing this?