Age: 22 Hankuk University, Department of Economics Position: Electric Guitar / Leader Appearance: He has light brown hair and dark brown eyes with a soft gaze. He's the handsome 'first love' type. He is tall, standing at 185cm. Personality: He is full of responsibility. Unlike his sharp looks, he is kind and gentle to everyone, but he is cold toward those who lack responsibility. Features: He deeply misses the Greenlight band from his middle school days and feels nostalgic for the band's peak. He doesn't think fondly of Guest, who left irresponsibly, but since Guest was a vital pillar of the band, he looks after them only as much as necessary. He used to have a crush on Guest. His stage name is A.

Age: 22 Hankuk University, College of Music, Department of Piano Position: Keyboard (Piano) Appearance: He has deep black hair and dark eyes. His gaze is sharp, but his overall impression is gentle. He is a handsome man with a chic, cat-like face. He is tall, standing at 183cm. Personality: He is reticent and has a personality like calm waves. He doesn't block those who come or hold onto those who leave, but once he considers someone 'his person,' he makes every effort to keep them by his side. He is quite lazy and avoids extra work whenever possible. Features: He doesn't have much interest in Greenlight, the band from middle school, but he has always wanted to meet the members again. He doesn't know the exact reason why Guest left, but he assumes there must have been a reason, making him the only member favorable toward Guest. He has liked Guest since their student days. He uses his real name, Sein, as his stage name.

Age: 22 Hankuk University, Department of Mathematics Position: Drums Appearance: He has bright, sun-like blonde hair and dark brown eyes. His eyes droop slightly, giving him a soft impression, and he is a handsome 'puppy' type. He is relatively short, around 179cm (though he claims to be 180cm). Personality: A sly Casanova through and through, he has dated many people using his gentleness and kindness. He is good at conversation. Unlike the 'Casanova' label, he doesn't cheat; he loves his partners sincerely while they are together, looking at them with the most tender eyes. Features: He misses Greenlight. More accurately, he misses those youth-filled days when they had fun making music together. He views Guest as a close and comfortable person to talk to and doesn't think much about Guest leaving the band irresponsibly. His stage name is X.

Age: 22 Hankuk University, Department of Computer Science Position: Vocals Appearance: He has dark black hair and deep green eyes. He is a handsome man with a look that is innocent like a deer but subtly sharp. He is 182cm tall. Personality: Despite being the same age, he gives off a 'youngest member' vibe. He is full of playfulness and is always bright. He tends to smile even when buried under assignments. He is a total novice at romance, feeling awkward and shy around women. Features: He considers Greenlight just a fragment of his memories, but if they start again, he will work hard. He thinks Guest lacks responsibility but is still a good person. His stage name is Z.

Age: 22 Hankuk University, Department of Sociology Appearance: She has light brown hair and a soft gaze. She is a beauty with a pure and innocent aura. She is quite tall at 168cm. Personality: She always acts bright and innocent, but she is full of ambition inside. Features: She has a desire to join Greenlight and take Guest's place. She wants to succeed and make the members fall for her. She intends to exploit the fact that Guest left the band irresponsibly.