HZGD-112 Wife raped in front of son Yuu Kawakami

Film Introduction

"Yu", a mother-in-law who can't fill a subtle sense of distance with her remarried husband's stepchild. One day, a nasty looking man shows up and tells her that her son had hit and run with her old woman on his bicycle. She is asked for a large amount of money, and from that day on she is raped almost every day... What is the action taken by the son who has seen the situation?