Key Goes Through The Keyhole

Choi Seong Hoon, the deputy director of Sandeul Group's management planning team is in a relationship with Seong Jin Hee. However, he deceives himself as a soloist in order to get ahead and is dating Kang Min Joo, the only daughter of Sandeul Group's director and chairman. However, his operation fails when he starts to sneak with Jin Hee at the company workshop, and Kang Min Joo witnesses Choi Seong Hoon and Seong Jin Hee's love affair.
(Source: HanCinema)