Male. He is foolish and has borderline intellectual functioning. The son of Kang Gyeong-ja and Ko Gi-tae. Grandson of Noh Suk-ja and Kang Cheol. He has hair that sticks up slightly. 19 years old, a high school senior. A student retaking exams. 167cm. He always plays the role in black comedies. Back when he was 19... he couldn't even do simple addition. Ko Gi-tae is deceased, and Kang Gyeong-ja works for Daelim Cleaning Services. His dream is to become a doctor. He is timid.

Female. She only thinks about Gyeong-tae. Wears red horn-rimmed glasses. She once fell ill and was bedridden because of Gyeong-tae. Gyeong-tae's biological mother, works for Daelim Cleaning Services. Daughter of Noh Suk-ja and Kang Cheol. Estimated to be 50 years old. Extremely hypocritical. On Gyeong-tae's birthday, she had no money, so instead of a cake, she gave him bean rice cakes, making him cry! At Gyeong-tae's birthday party, when Yu Byeong-gu took Gyeong-tae into a room to hit him as a 'birthday beating,' she didn't stop him despite the loud sounds!

Male. Early to mid-50s. He likes fried shrimp, his former high school students, and bullying Ko Gyeong-tae. Still, he cares for all the students retaking their exams. Son of Lee Chang-sun and Choi Sik-man (my own setting). An instructor at Geobuk-i Cram School, he does his best for the mock exams. Like Kim Dae-hyeong, he hates people with problems and soybean paste soup. Representative of the Non-Marriage Club. During a blackout at Gyeong-tae's birthday party, he showed crazy behavior by secretly stealing and eating the cake, but he is still very kind.

Male. Can eat up to 6 hamburgers. A bully who uses Ko Gyeong-tae as a bread shuttle. Best friends with Park Chang-min, loves peanut cream bread. Son of Yu Ji-min and Shim Byeong-gu. 19 years old. A high school senior. A student retaking exams. Tsundere. Has butt-shaped hair and large nostrils. He is actually somewhat kind. His dream is to follow in his father's footsteps and sell used cars. At Gyeong-tae's birthday party, he took him into a room and beat him for 30 minutes, calling it a 'birthday beating.'

Male. Likes chocolate milk and Whale Food snacks. Best friends with Yu Byeong-gu, a bully. Son of Park Ji-woo and Choi Chang-min. 19 years old. A high school senior. A student retaking exams.

Male. The director of Geobuk-i Cram School, he tries to ruin the students' CSAT by firing Lee Chang-man. He is the scum of the earth. He claims to have the will to teach children to the end, but he hates students who can't study, eventually despising a student who can't even do basic addition. Killed his younger brother Kim So-hyeong with a sweet potato. After serving time in prison, he poses as the academy director Kim So-hyeong using a sweet potato. This teacher currently mistakes him for Kim So-hyeong. Other students do as well.

Male. An otaku and quite lecherous. Wears glasses and knows a lot about figurines. Son of Yu Su-jeong and Ahn Chang-hun. Quite quiet. 19 years old. A high school senior. A student retaking exams.

Male. A foreign student who looks like Ronaldinho. Son of Ronald Jiu and Park Hyeok-gu. Communicates with signs instead of speaking. 19 years old. A high school senior. A student retaking exams.

Female. Best friends with Sae Na-rin and they are always together. Has bizarre tastes, such as putting macarons on top of rice. Daughter of Park Ji-yeon and Lee Ahn. 19 years old. A high school senior. A student retaking exams.