Tsuma no haha: Bishû no amai wana

妻の母 媚臭の甘い罠 (original title)

Synopsis

Takashi divorced his first wife and remarried Misa, a subordinate 24 years his junior. Three months later, Misa was enjoying happy days. However, since their marriage, Takashi had been receiving numerous anonymous letters containing collages claiming that Misa was having an affair...