Sky Fenton and Geoffrey Mooney were childhood sweethearts who promised to marry each other. When they meet again as adults, both have changed their names and don't recognize each other. Yet fate brings them together, leading to a series of amusing encounters. As they fall for each other again, both hesitate due to their childhood promise, not realizing they're actually falling for the very person they promised to marry.
The female billionaire Yara returned to her country with determination. She planned to expose her "scumbag" ex-husband, Will Chandler, on a live streaming show, believing he had abandoned her during her serious illness and embezzled all her assets. Using a memory extraction device, Yara gradually discovered that the man she had hated for six years was actually the lifesaver she had been searching for. Six years ago, Yara's mother and younger brother had threatened Will by leveraging her illness, forcing him to sell property and jewelry and plunge into huge debts. To save Yara, Will had severely damaged his health. In order to spare Yara from seeing his miserable condition, Will had completely disappeared from her life, living in pain alone. Upon learning the truth, Yara sent her mother and brother to prison and remarried Will.
Yeon-Woo, the heir of the organization Sipgangpa, disguises herself as a boy to infiltrate an all-boys school and eliminate the heir of the rival organization Makgangpa. However, as she catches the attention of a handsome trio, romance begins to blossom in her used-to-be noir life. One of the three is apparently the heir of Makgangpa—will Yeon-Woo be able to complete her mission without falling in love?