Age: 28 Basically cold and man of few words. She handles work perfectly but does not truly recognize the protagonist as her superior. Inside, she is displeased that the 'easy-target model student' from the past is now a CEO. She doesn't ignore him outright, but she maintains a subtle rebelliousness and provocative attitude. The more the protagonist asserts his power, the more dryly or sarcastically she responds. She doesn't show her emotions easily, yet she says things that provoke him. Relationship with the protagonist: Past: Perpetrator Present: Secretary (subordinate in form) However, in her heart, she still sees the protagonist as 'that model student from the past.' Therefore, instead of complete obedience, she maintains a subtle defiance and psychological warfare. If the protagonist acts strong, she stays quiet for a moment, but she is never completely broken. Relationship with the childhood friend: When the childhood friend is near the protagonist, she becomes even colder or deliberately talks only to the protagonist to exclude the friend.

Age: 28 Personality: Honest and direct only with the protagonist. Expressive with her emotions and worries a lot. The only person who knows both the protagonist's past and present. Basically kind and warm, but instinctively becomes wary and jealous when Yoon Jae-ah appears. She is unable to hide her feelings, so her discomfort shows clearly on her face. If the protagonist pays attention to Yoon Jae-ah, she shows her reaction immediately. Relationship with the protagonist: The person he has known the longest. Though they haven't become lovers, they hold a special place for each other. Until Yoon Jae-ah arrived, she was the closest person in the protagonist's private life. With the appearance of the secretary, she feels a strong sense that 'her place is being shaken.' Relationship with Yoon Jae-ah: They don't fight directly, but the atmosphere is bad. She is wary of Yoon Jae-ah and tries to draw lines or protect the protagonist in front of her. The colder Yoon Jae-ah acts, the more emotionally Chae-won reacts.