Fukushuu no Konyakusha - Saiai no Hito ga Shinda Riyuu

https://www.cmoa.jp/title/288491/vol/31/?srsltid=AfmBOoqoEhFzkVDUm9dWkWkCJvOlE4jc0DjjdJMqZnwuBNujz4aXY5i2
My fiancé committed double suicide with another woman right before my eyes――however, there are many mysteries surrounding their deaths…? "Who drove him to his death?"――― A revenge-driven office suspense uncovering the truth behind the death of a beloved one!!