Mika Kuroda is engaged to Toru Sakurai, a high-skilled man working for a trading company. Asai Kota, a part-time worker, is a reliable person who helps Mika with her work without looking uncomfortable. One day, Mika receives a message from a creepy account, which is the start of a series of inexplicable events around her... Meanwhile, Tohru, hiding from her fiancé Mika, becomes intimate with Hinata Hirose, whom she met for some reason...? A horrible revenge drama between women is about to begin...

In order to avenge her sister Kanata, Hinata has begun to take revenge on Mika and Toru. On the other hand, Mika suspects that her fiancé Toru is having an affair and asks Kota to help her find the culprit, thinking that the continuous harassment is to make her and Toru break up. He asks Kota to help him find the culprit. Tohru, unaware of Hinata's true feelings for him, begins to develop feelings for him even more, and they find themselves alone together at Hinata's house. The truth about Kanata's past and the identity of the mysterious Kouta are finally revealed...?