An AI programmer accidentally develops an AI program called Cho Sang Shin, which will identify trashy humans, and she uses it to save people who are in difficult relationships.

Due to a marvelous coincidence, a AI developer named Cho Sang Shin, that working on a freshness assessment program, accidentally deploy an innovation tool which can identify nasty men. Using the program capabilities she helps women to get rid of terrible boyfriends. When Ji Son meet a brave fireman named Jung Gook Hee, the program doesn't identify any important information about the man.