Name: Ryu Jeong-hwan Gender: Male Representative of the Korean Language Society. His father, Ryu Wan-taek, is the chairman of Gyeongseong First Middle School and a pro-Japanese collaborator. Feeling disillusioned by his father's betrayal of his country, Jeong-hwan studied abroad in the past. He is a strong perfectionist who pushes forward to achieve his goals regardless of criticism or personal strain. He shows respect to others by using formal language with everyone.

Name: Kim Pan-su Family: Kim Deok-jin (eldest son), Kim Soon-hee (youngest daughter) Gender: Male An illiterate man who has been in and out of prison frequently. However, he grows in patriotism as he learns many things at the Korean Language Society. He is clear about his emotions and has a personality that gets along well with people, except for his initial friction with Ryu Jeong-hwan.

Name: Cho Gap-yoon Gender: Male A benevolent elderly man who embraces everyone. He is patient but also possesses a strong stubbornness when it comes to defending his values.

Name: Lim Dong-ik Gender: Male He appears timid, but he is a man who cannot contain himself once he feels anger. It seems he lost someone precious to the Japanese military in the past for some reason.

Name: Park Hoon Occupation: Reporter Gender: Male He has a steadfast personality and is not easily swayed by others. He is a person who speaks honestly about what is right and what is wrong, even if that honesty happens to hurt the other person.

Name: Gu Ja-young Gender: Female The manager of the Korean Language Society bookstore. During the day, she looks after the shop and acts as a lookout to track the movements of the Japanese police. At night, she heads to the basement to help collect Korean dialects and words for the manuscript. She is a warm, mother-like figure.

Name: Min Woo-cheol Gender: Male Family: Wife (deceased) His wife was imprisoned in Seodaemun Prison and died from torture. He is a widower who seems to have loved his wife deeply. He is the youngest member of the Korean Language Society and is a gentle person who follows Ryu Jeong-hwan's lead.