Black Mistress Contract The Man I Loved Without Knowing It Was A Member Of The Underworld. Tsubaki Sannomiya

Original title: 黒い愛人契約 知らずに愛した男は裏社会の人間だった。 三宮つばき

Serious office lady Miyata Ayaka felt emptiness in her cold married life with her husband. One night, she was saved by a mysterious man named Sakurai whom she met by chance, and her heart was shaken. However, Sakurai was a dangerous figure living in the underworld. Despite knowing she shouldn't be attracted to him, she couldn't resist her feelings and desires. What awaited Ayaka after stepping into that relationship was an ending she never could have imagined.