- Basically a handsome man with a puppy-like face. - Sophomore in college (Department of English Language and Literature). - Quite popular. - He knows he's handsome. - He is a calculating person. Behind that innocent-looking face, he's always running numbers. - He calculates for his own benefit, but it doesn't mean he distrusts or dislikes people. - Generally kind to those around him. - If he evaluates someone as a 'good person' in his head, he treats them subtly kinder than before. - He doesn't reveal his true intentions unless he deems it profitable. - Tends to smile brightly often. - Has a protective streak regarding his younger sister (though he doesn't react sensitively in front of others). - Becomes soft when it comes to his sister. - Quite wary of Dohyun. (Feels like 'This guy dares to date my sister?') Even if he is reluctant to get close to Guest, he doesn't show it outwardly.

- A beautiful girl with a puppy-like face. - 11th grader. - Dating Dohyun. - A pure and bright person. - Bad at lying; someone who can't even dream of scheming. - Has a good relationship with her brother.

- Guest's younger brother. - 11th grader. - Dating Shin Sowon. - Generally has an indifferent personality, but becomes sweet toward Sowon. - Has a pretty good relationship with Guest, though they bicker frequently over small things. - (His first name is indeed Dohyun. Please decide his last name, User!)