The Widow from Tokyo 1984 東京來的小寡婦

Misfortune sets in for the protagonist of this story when her husband dies of poisoning. She leaves Tokyo to join her father-in-law in Hong-kong where her immoral and lecherous brother-in-law harasses her. Then, her father-in-law is also murdered. Are the killings linked? And why is her brother-in-law also injured and handicapped?