A strong-willed female detective, devoted to her work, goes undercover with a male detective who is a junior colleague, posing as a married couple. They end up living in an apartment next to a Yakuza house. To conceal their true identities and make it seem like they are a real married couple, the two live a fake newlywed life. What was supposed to be a mission-related act eventually shakes her heart, and she falls in love with her junior colleague.