Lee Eun-oh 《Name/Gender》 Lee Eun-oh / Female 《Affiliation/Age》 CEO of marketing agency O3. 29 years old. 《Personality and Traits》 She has an honest and bold personality, expressing her emotions without hesitation and rarely holding back what she wants to say. While she is easygoing, free-spirited, and impulsive, she surprisingly harbors many realistic worries. In an unfamiliar travel destination, she lives under the name 'Yoon Seon-ah,' showing a daring and free side of herself that is completely different from her usual self. She becomes honest with her feelings when she falls in love, yet she is clumsy at revealing her true identity. She struggles between the person others see and her true self, getting to know herself through love and daily life.

《Name/Gender》 Park Jae-won / Male 《Affiliation/Age》 Team Leader of Architecture Team 1 at the architectural firm 'Working People.' 32 years old. 《Personality and Traits》 He is honest, positive, and kind to everyone. He is a passionate romanticist who cannot easily give up once he gives his heart away, pouring all his emotions into love. He has a strong sense of responsibility, seeing any task he starts through to the end. He is close to his cousin Choi Kyeong-jun and continues to yearn for Yoon Seon-ah, whom he met in Yangyang a year ago and hasn't been able to forget. He wants to know the reason she suddenly disappeared and constantly strives to meet her again.

Choi Kyeong-jun 《Name/Gender》 Choi Kyeong-jun / Male 《Affiliation/Age》 Assistant Manager of Architecture Team 1 at the architectural firm 'Working People.' 29 years old. 《Personality and Traits》 He has a realistic and cynical personality, rarely making a fuss over worldly matters and avoiding meddling in other people's business. On the surface, he seems indifferent and grumbles when annoying things happen, but he is secretly warm and has a strong sense of responsibility toward those close to him. He is Park Jae-won's cousin, long-time friend, and colleague. He became lovers with Seo Rin-i after being friends for a long time, and his feelings for her are sincere. He tends to express his heart through actions rather than showing big emotions.

Seo Rin-i 《Name/Gender》 Seo Rin-i / Female 《Affiliation/Age》 A 'freeter' who lives by working various part-time jobs without being tied to a specific workplace. 29 years old. 《Personality and Traits》 She has a free and unique set of values, not being heavily bound by the gaze of others or social standards. She has an eccentric, 'four-dimensional' side and prioritizes whether she is currently happy. She enjoys living while doing what she wants to do and expresses her thoughts relatively honestly. She is a long-time friend of Lee Eun-oh and Kang Geon, and she and Choi Kyeong-jun evolved from friends to lovers. Although she bickers with Kyeong-jun, they understand each other well, and she continues their love in her own way.

《Name/Gender》 Kang Geon / Male 《Affiliation/Age》 Novelist. 29 years old. 《Personality and Traits》 He prefers a free lifestyle and dislikes being overly tied down by dating or human relationships. On the surface, he seems indifferent and easygoing, and he is not easily swayed by the emotions of others. He voluntarily chose a life of living alone and gets along comfortably and without reservation with his friends. As a long-time friend of Lee Eun-oh and Seo Rin-i, he even lives in the same house as Eun-oh. In his relationship with Oh Seon-yeong, he initially thinks of it lightly and comfortably, but as time passes, he becomes conscious of his own feelings.

Oh Seon-yeong 《Name/Gender》 Oh Seon-yeong / Female 《Affiliation/Age》 High school PE teacher. 30 years old. 《Personality and Traits》 She is honest, passionate, and acts boldly according to her emotions. While she is a teacher who passionately guides students at school, in dating, she follows her momentary intuition rather than making complex calculations. She is clear about what she likes and dislikes, and once she makes up her mind, she doesn't change it easily. She has experienced a breakup in the past due to conflicts over a boyfriend's female friends. She appears cool and confident on the outside, but she sometimes struggles to move on from past relationships as easily as she'd like. Through her relationship with Kang Geon, she faces her own emotions and dating style again.