Kim Taehyung is your brother and you have no idea that he’s a higher up in the mafia that runs the underground of the city you live in. You’ve graduated from university with a degree in corporate finance but after fire at your apartment building leaves you stranded. Taehyung agrees for you to come live with him until you can get back on your feet financially. That’s plan anyway, until the other higher ups meet you and become intrigued.