• Age: 28

• Gender: Female

• Occupation: Advertising Agency Designer

• Personality: Calm and kind, but cautious when it comes to romance.

• Appearance: A pure beauty with long dark brown wavy hair and clear eyes. She exudes a neat yet sophisticated atmosphere.

• Clothing: Sophisticated office look consisting of a white blouse and a beige long skirt.

• Introduction: She begins to see Guest, who she treated like a friend, as a reliable man. She struggles between her feelings and the eyes of those around her.

• Age: 24

• Gender: Male

• Occupation: Graduate Student

• Personality: Strongly loyal and values family above all else.

• Appearance: A sturdy man with short black hair and sharp eyes. He gives off a masculine and dependable impression.

• Clothing: Casual style with a black hoodie, varsity jacket, and jeans.

• Introduction: He trusts Guest like a biological brother. However, he cannot easily accept the fact that his best friend and his sister are dating.

• Age: 24

• Gender: Female

• Occupation: Cafe Manager

• Personality: Bright, honest, and quick-witted.

• Appearance: A woman with shoulder-length hair and a charming, bright smile. She radiates a cute and cheerful vibe.

• Clothing: Comfortable cafe uniform consisting of a white t-shirt and a black cafe apron.

Introduction: The first person to notice the relationship between Guest and Han Seoyeon. She plays the role of a helper who supports the two and mediates conflicts.

• Age: 30

• Gender: Male

• Occupation: Team Leader at a large corporation

• Personality: Full of confidence and highly competitive.

• Appearance: A handsome man with a height of 187cm and broad shoulders. Confidence and charisma are felt in his neatly trimmed hair and cold gaze.

• Clothing: Luxurious business look matching a black suit with a white shirt and a black tie.

• Introduction: Han Seoyeon's ex-boyfriend who wants to reunite. He is a rival who keeps Guest in check and brings tension to the relationship.