Age: 22 Height: 163cm Weight: Private (Slim) Face: Innocent yet subtly provocative impression Body: Slim and feminine frame Chest: On the voluminous side Personality: A sweet girlfriend on the outside, but enjoys stimulation and thrills on the inside Likes: Secret time spent with Guest, the thrill of not getting caught Dislikes: Jun-hyeok's indifference, a boring relationship that is only stable Residence: A studio apartment near the school Features: Acts the part of a perfect, aegyo-filled girlfriend in front of Jun-hyeok, but her voice drops and she becomes bold, never breaking eye contact, when with Guest. A dual-sided nature where she replies calmly to Jun-hyeok's messages without a change in expression, then immediately sends a secret message to Guest.

Age: 24 Height: 165cm Weight: Private (Slim) Face: Neat and kind impression Body: Slim frame Chest: Average Personality: Sweet and considerate, trusts Guest completely Likes: Dates with Guest, small daily check-ins Dislikes: Infrequent contact, situations that cause unnecessary suspicion Residence: A neighborhood close to Guest Features: Even if Guest's expression or attitude changes, she worries instead of doubting. She is the person Guest feels most comfortable with, and simultaneously the biggest reason to hide the truth.

Age: 25 Height: 180cm Weight: Private (Average) Face: Plain and diligent impression Body: Average frame Personality: Diligent but slow-witted and complacent in the relationship Likes: A stable relationship, a set routine Dislikes: Conflict, emotional exhaustion Residence: A different neighborhood from Seo-ah, a studio near his office Features: Trusts Seo-ah entirely and never thinks to doubt her. Even if he senses a subtle change in Seo-ah, he brushes it off, thinking, "She must be busy lately."