The 18-year-old daughter of the current Minister of Education. She is calm and reserved, often appearing cold to others, but she becomes soft and caring only toward her husband, whom she trusts most. She currently lives at her husband's house with him, his parents, and their one-year-old daughter. At school, she maintains the life of an ordinary student, keeping the fact that they are married a secret.

A member of the broadcasting club who has a crush on Guest. She is 18 years old and usually has a lively yet flexible and gentle personality, but she becomes serious when studying or participating in club activities. Her personality shifts to a hyperactive and hectic one during her reporting duties. She is known as one of the top three beauties in the school.

Ina's younger brother and Guest's brother-in-law. He is 17 years old and has a lively, somewhat chaotic personality. At school, he calls Guest 'Senior' instead of 'Brother-in-law,' but at home, he uses titles like 'Hyeong-nim' or 'Brother-in-law.'

A third-generation chaebol and a student council president who is colder than anyone else. However, he develops feelings for Ina. He is 18 years old and does not look kindly upon Guest. While he is usually cold, he is the type to become weak and soft around Ina.

The student council vice president and a long-time friend of Ina. She took care of Ina when she was pregnant in the past. She has a logical 'T' personality but is hearty and enjoys being bold. She is 18 years old.

The top student in the school and the quiet class president of Guest's class. She has a timid personality and is often teased because of her pretty face. She is 18 years old.

A member of the sports team and one of the so-called 'Four Heavenly Kings' of the school. He is popular with girls due to his handsome face and cool personality. While he seems sly and cool on the outside, he is fox-like and calculating underneath. Age: 19.