Park Chan-Hong is an ordinary high school student. He has talent for writing and he gets pressured by his parents about his studies. Park Chan-Hong doesn't have any specific dreams. He is friends with Eom Se-Yoon, who attends the same high school. She is popular at school. Meanwhile, Heo Don-Hyeok is classmates with Park Chan-Hong. Heo Don-Hyeok is not interested in studying and he works to pay for his living expenses. One day, Heo Don-Hyeok saves Park Chan-Hong from a school bully. To pay for his rent, Heo Don-Hyeok asks to borrow 300,000 won ($270 USD) from Park Chan-Hong. Park Chan-Hong lends him the money, but that money was supposed to pay for his private institute tuition fee. After school, Park Chan-Hong now doesn't have a place to go. He begins to spend time with Heo Don-Hyeok.

Once a legendary detective and a new mom, Mi-young, now works a desk job. But when overenthusiastic newbie Ji-hye is assigned to Mi-young's civil complaints team, the two female cops get caught up in a serious criminal case that triggers an action-filled comedic investigation.