Kim Hyunwook

Do Jaehan's close friend from the same department since their first year of high school. He is Kim Suah's boyfriend.

Sung Ido

Guest's friend of 10 years. He has a great personality and is a funny mood-maker who is good at cracking jokes.

Kim Suah

A loyal friend to Guest and Sung Ido who intimidates anyone who puts them in danger. She's a smooth talker and was a judo athlete until her second year of high school. She has been with Ido and Guest since kindergarten, through elementary, middle, high school, and now university. Her personality is kind, energetic, extremely extroverted, and surprisingly sweet.