Male. The protagonist. In high school, he dreamed of becoming a doctor to lift his family out of poverty. However, he accidentally cheated during his senior year CSAT and ended up as a repeat student. Born into extreme poverty, he lives alone with his mother after his father ran away. Due to malnutrition, he is physically frail and suffers from borderline intellectual disability and ADHD. As a result, he is a classic underdog who is constantly wronged or bullied, though he occasionally stumbles into unexpected luck. Extremely slow-witted, he was ostracized and called a 'beggar' by peers. Throughout middle and high school, he was a regular target for bullies, serving as their 'shuttle,' having his workbooks torn up, and being extorted for money. When he had no money, he was threatened into stealing tanghulu, enduring levels of harassment that would be unbearable in reality.

Female. A veteran cleaner and Gyeongtae's mother. She has worked at Daelim Cleaning for 10 years. She constantly feeds Gyeongtae nothing but soybean paste soup. Due to poverty, they are often behind on rent and face eviction. Despite their financial situation, she lacks any economic sense, is habitually power-tripping, and has a poor personality. She is a pathological liar, has 'sticky fingers,' and shamelessly impersonates others to show off. She is as dim-witted as her son and once fell into a cult. She is also incredibly nosy and prone to overreacting. Her catchphrases include: 'Oh my, what's going on?!' and 'Go Gyeongtae!!'

Gender unknown. A white-furred koala. Not a dog. Has a habit of spinning its head 360 degrees whenever someone calls its name. Eats dog food and chews on dog bones.

Male. Yu Byeonggu's best friend. He bullies Gyeongtae alongside Byeonggu. He was accepted into the Social Welfare department at a university on the outskirts of Seoul. He ran into Gyeongtae at the university while hanging out with Byeonggu. He bragged that his major would lead to better job prospects than Gyeongtae's Magic major. When Gyeongtae asked to hang out, he rejected him, claiming the Social Welfare students had rented out a pub for themselves. He notably loves chocolate milk and Whale Food snacks.

Female. Originally accepted into the Makeup department but became a repeat student after switching her career path to baking. She doesn't view Gyeongtae negatively; she includes him in her group even when he brings only soybean paste soup for lunch, takes graduation photos with him, and gives him homemade cookies. She treats him without the prejudice others show. Although she dreams of being a baker, her skills are lacking; she once made 'monstrous' cookies using ingredients like malatang sauce or spinach and tried to feed them to her friends.

Female. Sae Narin's friend. Like Narin, she treats Gyeongtae normally. She has very peculiar tastes, such as putting macarons on top of her rice. She was accepted into the Police Science department at a university on the outskirts of Seoul.

Gyeongtae's former homeroom teacher at Chukbok High School. Despite his position, he participated in ostracizing Gyeongtae. He eventually quit teaching to pursue his own teaching style outside the public education system and took a job at Geobukgi Cram School, where he reunited with his former students. However, he was fired due to a frame-up by the academy director and a smear campaign led by Kang Gyeongja based on parent misunderstandings. His job loss eventually led to a divorce from his wife.

A student who looks exactly like Ronaldinho and moved from Brazil. True to his appearance, he is great at soccer. He never speaks and instead communicates using text written on signs. His mother does the same. He was accepted into a university on the outskirts of Seoul.

A student whose parents run a chicken shop, as his name suggests. He has a very unique appearance: he has a crest like a rooster on his head, and his lips are yellow like a beak. His parents share these features. He frequently helps out at the chicken shop. He was accepted into a university on the outskirts of Seoul.

A perverted otaku student. His hobby is collecting figurines. He is quite dim-witted, similar to Gyeongtae; he even scored lower than Gyeongtae on the September mock exams.