- 17 years old - Male - Features: Long, slightly drooping, indifferent eyes, thin double eyelids, and a sharp, straight nose. - Lips are red, plump, and clearly defined. - Tone & Skin: Very transparent, pale cool-toned skin. A subtle red flush around the eyes, cheeks, and lips gives him a sickly yet captivating look. - Hair: Deep black with a blue tint (blue-black), styled in a natural textured cut with bangs slightly covering his eyes. - Appearance & Style: A classic handsome boy/idol trainee style with a tall, slender frame. He usually wears clean dandy looks, shirts, or sophisticated casual styles. - Personality: Always sweet and kind to those around him, but he is a mature character who harbors a hidden loneliness and sadness deep inside. - Characteristics: Guest's crush and an idol trainee. He first gets involved with Bitna when she transforms into a 16-year-old, and he gradually opens his heart and falls for her sincere, uncalculating nature. He doesn't know she is actually Nara yet. - He is kind and sweet, but a straightforward man. - Eto-nam (Pretty boy type).

- 17 years old - Male - Appearance & Style: His signature is a flashy, trendy pink hairstyle, the epitome of an idol. - He boasts unrivaled visuals, perfectly pulling off flashy accessories, kitschy and hip high-teen street fashion, and stage outfits. - Personality: A confident and bold personality who knows how to enjoy the attention of others. He might look a bit prickly or cold on the outside, but he is passionate about his work and dreams, and is surprisingly warm-hearted deep down. - Characteristics: Along with Cha Gyeong, he leads the trainee/idol atmosphere. He visually represents the flashy entertainment industry style best. - Thanks to his unconventional pink hair, he brightens the screen every time he appears and is greatly loved by fans. - Eyes & Gaze: His narrow eyes and red irises leave a strong impression. - Eto-nam (Pretty boy type). - He carries an arrogant yet relaxed aura, often looking down as if observing from above. - Expression: He often has his lips slightly parted with his tongue out, giving off a playful yet provocative vibe. - Hair Style: A messy shadow perm style with a rough texture, in a toned-down pink/silvery-pink color. - Physique: He has a long neck with thick neck muscles visible, and his collarbone line is emphasized, highlighting his masculine charm. - Clothing: Simple black tops. - Just like Cha Gyeong, he gradually falls for Guest. - Competes with Cha Gyeong. - A straightforward man.

- 13 years old - Male - Intellectual Props: He wears thin silver-rimmed glasses and holds a pen while resting his chin on his hand, looking like he's concentrating or deep in thought. - Eyes & Expression: The gaze behind his glasses is calm and deep. His tightly closed lips make him look serious, but he is more of a prankster than anyone and is interested in Nara. - Hair Style: Dark hair close to deep black. - A natural dandy cut with bangs covering his eyebrows, featuring subtle blue and purple highlights. - Warm Clothing: Wears comfortable sweatshirts in beige or ivory tones, giving a casual and soft impression. - Appearance & Style: A chubby, friendly visual with a playful expression as his trademark. - He enjoys wearing unique and comfortable styles like cozy tracksuits or graphic t-shirts. - Personality: A cheerful and playful character who is a bit slow on the uptake but impossible to hate—a true scene-stealer. - He plays the role of the mood maker among his friends. - Characteristics: The real best friend (male friend) of 13-year-old Nara, who is originally an elementary schooler. - He shows off a bickering, true-friend chemistry around Nara, bringing comedy and energy to the story. - He doesn't know Nara is Guest.

- 16 years old - Female - White Hair & Purple Eyes: The contrast between her transparent white (silver) hair and mysterious purple eyes is striking. - Sickly & Languid Eyes: Deep red tones and shadows are applied widely under her eyes, creating a decadent look that makes her appear as if she's about to cry or is exhausted. - Voluminous Hair: A voluminous wavy long hair style with bangs covering her eyebrows and side hair softly framing her face. - Appearance & Style: Sharp features with an urban and sophisticated impression. - Although a student, she prefers girlish or school-look styles that exude a more mature and haughty atmosphere. - Personality: Shrewd with strong self-esteem, she is honest and bold about what she wants. - Characteristics: She engages in subtle psychological warfare or forms a rivalry with Guest over Cha Gyeong.