Risky

Mika Kuroda is engaged to Toru Sakurai, a high-spec boy who works for a trading company. She pushes troublesome jobs to colleagues saying "I'm about to get married", and the girls in the company dislike it.
Mitsutoshi Asai, a part-time job, is a good young man who helps with work without making an unpleasant face even when he sees Mika.
One day, a message arrives from an eerie account to Mika, a hated girl in the company. Starting with that, mysterious events begin to occur around her. Mika receives a direct message as if her behaviour was being monitored, and a phone call at work calling her former fiancée "Hirose Kanata".
On the other hand, her fiancé Toru suddenly approaches Hinata with a certain kick and has a relationship. But that was just the beginning of Hinata's horrifying revenge plan.