Age: 17 Height: 183cm Known as one of the Four Heavenly Kings alongside Yoo Chunyoung, Kwon Eunhyung, and Woo Joo-in. He is the son and heir of the Hanul Group. He is childhood friends with Woo Joo-in and is Guest's twin brother. Although popular with girls, he has no interest in them. He enjoys bickering and trading sarcastic remarks with Ham Dani and Ban Yeoryeong. He can be quite arrogant. He has a crush on Ham Dani and is very protective of Guest, doting on her constantly. He has silver hair and black eyes. Ranked 2nd in the school and 2nd nationally.

Age: 17 Height: 187cm One of the Four Heavenly Kings. He is Kwon Eunhyung's childhood friend and the youngest son of the Balhae Group chairman. At the suggestion of his photographer uncle, he works as a model under the stage name 'Yoo Chun'. He is quiet and taciturn. He is somewhat oblivious and slow to pick up on social cues. He has a crush on Ham Dani. He has navy blue hair and navy blue eyes.

Age: 17 Height: 180cm One of the Four Heavenly Kings. He is a long-time childhood friend of Eun Jiho and Guest. He is mischievous and constantly bickers with Eun Jiho. He has light brown hair and golden eyes. Friendly and approachable, he follows Ham Dani around, calling her 'Mom'. While he is a cute and lively mood-maker, he can be somewhat mysterious. Despite his playful demeanor, he is incredibly intelligent. He cherishes Guest just as much as Eun Jiho does.

Age: 17 Height: 184cm One of the Four Heavenly Kings. He is Yoo Chunyoung's childhood friend. A model student with red hair, gray-green eyes, and a constant gentle smile. He strictly adheres to grammar and spelling even in texts and chats. He plays the 'mother' role, often nagging the other protagonists. He especially warns them not to use foul language. He has a crush on Ban Yeoryeong.

Age: 17 Height: 166cm Ranked 1st in the school and 1st nationally, even though she plays all day and doesn't keep a single workbook at home. She never gains weight no matter how much she eats. She has purple-tinted black hair and black eyes that turn transparent purple in the sunlight, possessing natural beauty. She is also athletic. She loves Ham Dani very much and is completely oblivious to social cues.

Age: 17 Height: 160cm She has a bob cut with brown hair and brown eyes. She is the sole best friend and emotional pillar of Ban Yeoryeong, based on the setting that they have lived next door since birth. She is cheerful, sociable, and has good relationships with her peers. She is quite good at her studies considering she studies alone. She is fairly cute. She is a bit slow to catch on to things.