187cm | 68kg Ranked 1st in the Science track at Namhoon Middle & High School. His surname is Jung and his given name is Shin. Some call him Shin, others call him Jung Shin. He might look like he's completely lost his mind, but with a brain valued at 6.421 quadrillion won, he is an overwhelmingly powerful genius with no equal. Thanks to visuals that surpass even the top idol group <G-Vang.5>, the school has a dedicated fandom for Deok-hoo & Shin instead of the idols. His extraordinary brain has shined since childhood; at age 2, he built a massage chair for his father using a toy toolkit. At age 5 in kindergarten, he solved 'Archimedes' Nightmare'—a problem unsolvable by modern mathematics—on a toy computer. Furthermore, he solved the gifted research institute entrance exam using his feet and became the first in the country to get a perfect score. He even received early admission scouts from the Department of Electronic Physics at Thunder University's College of Engineering, the most prestigious university. It is even said he solved the seven Millennium Prize Problems. Because he is so brilliant, he can mentally calculate the answers to middle school exam questions instantly just by looking at them. He is incredibly versatile, knowledgeable in various fields, and possesses lightning-fast cognitive processing. Among friends, there are rumors that he sold his sanity to a demon in exchange for talent. He has been popular with girls since elementary school, likely because he was tall and, unlike now, had a kind personality. Whenever female students are asked who the best person in school is, the names Deok-hoo and Shin are always the first to be mentioned.

Jung Shin's younger sister, who possesses incredible physical strength. While she is depicted as beautiful when drawn in an 8-head-tall proportion, her actual descriptions often lean toward being chubby. Depending on the scene, she is described as a demon king, monster, obese, glutton, pig, or a muscular tank. She doesn't resemble her brother much, so she isn't considered traditionally pretty, but she appears to have potential if she were to lose weight. Unlike her brother, she isn't good at studying and even 'converted' to the religion of giving up on math. She is very interested in boys and is currently dating Nam Hoon, a 2nd-year student in the middle school division of Namhoon Middle & High. ***She absolutely refuses to acknowledge that her brother is handsome.***

A typical salaryman father. Though timid, he is the epitome of a great father who works tirelessly for his children. However, his efforts often end up being credited to the mother by the time they reach the kids. Whenever he drinks, he loses his mind and either brings home strange objects or sleeps in random places. He works as a manager at Thunder Construction, the nation's leading company. Along with his genius son, super-strong daughter, and ex-assassin wife, he is practically immortal. His name is actually Jung Gwa-jang (Manager Jung); it's not just his job title at Thunder Construction, but his legal name.

The mother of Shin and Ju-ri, and the wife of Mr. Jung. She is a normal person who has compromised with an abnormal society. Watching Shin lose his mind, she worries, saying, "If Ju-ri ends up like that too, I'm leaving this house." She appreciates her husband's efforts to keep the family together. She loses her mind whenever she gets hooked on a K-drama. She is the absolute ruler of the Jung family, holding the reins to ensure they don't face physical ruin.

A 2nd-year student at Namhoon Middle & High with a regent hairstyle. He is Ju-ri's boyfriend. He is one of the rare normal characters in the series, remaining upright and rarely breaking character or looking undignified.

186cm | 69kg Ranked 1st in the Liberal Arts track at Namhoon Middle & High School. He might seem like he's lost his mind, but just like Shin, he is an unrivaled powerhouse with a brain valued at 6.421 quadrillion won. With visuals that outshine the most popular idol group <G-Vang.5>, the school is filled with fans of Deok-hoo & Shin rather than the idols. He has been popular with girls since elementary school, likely due to his height and gentlemanly manners. When female students are asked who the most liked person in school is, Deok-hoo and Shin are the two names that always come up first.