Name: Geo | Gender: Male | Age: Early teens | Height: 150cm | Nickname: Survival King The protagonist of the Survival Geo series. He first appeared in the Virus volume, the start of the Geo series, alongside Pipi and Kei. Since then, he has appeared in every single volume released to date, serving as the longest-running protagonist of the ongoing Survival series. Characteristics: A boy nicknamed the self-proclaimed and widely recognized 'Survival King.' True to his name, he is well-versed in survival common sense and possesses an instinctive sense for staying alive. Despite being an elementary schooler, he possesses immense physical strength and mental fortitude. Due to the nature of the manga, he is fated to get caught up in all sorts of disasters and accidents, but he never despairs and overcomes crises alongside those around him. Comparison with previous protagonists: Compared to protagonists of earlier Survival series, he possesses far superior intuition, physical strength, athletic ability, rational judgment, and general knowledge. He responds calmly to any situation and maintains a positive mindset. Unlike previous protagonists like Leo, Duri, and Momo, who often required adult help, Geo is a 'complete' character who comforts other children and survives through his own abundant knowledge even when no adults are present. While earlier series focused on the protagonists saving their own lives, Geo's stories often involve him saving others. He is frequently seen rescuing friends in danger or giving courage to those around him. In the Allergy and Trash Island volumes, he even steps up to save others even when he himself isn't in immediate danger. Because of this, fans jokingly praise him, saying, 'While the Survival seniors were busy saving their own skins, Geo travels around saving the world.' Nerfs: However, as the series progressed, there were many instances where his personality or intelligence were nerfed. Starting from the Climate Change volume after the masterpiece Virus volume, his 'nuisance' traits were strengthened. From the Tidal Flat volume onwards, his personality became more childish and ignorant to the point where fans wondered if he was the same person from the Virus volume. Before the Tidal Flat volume, he balanced his survival skills with the traits of a normal child.

Gender: Male | Age: 40s to early 50s. Everyone calls him 'Doctor.' A regular character in the Survival Geo series. While not appearing as frequently as the main trio (Geo, Pipi, Kei), he is a recurring supporting character. He is a doctor and inventor who first appears in the Human Body volume and calls himself a genius. He has Kei as his assistant. His real name is Noe Si-gyeong. He has a clumsy, easygoing personality and loves sweets. While his primary profession is a medical doctor, in the style of learning comics, he spends his time inventing all sorts of gadgets. He especially loves candy.

Name: Kei | Gender: Male | Age: Early to mid-20s | Occupation: Medical Student → Graduate Student A sub-protagonist of the Survival Geo series. He has appeared since the beginning alongside Geo and Pipi. He is a classic tsundere who constantly nags them but also looks after them and helps resolve situations. He usually handles the scientific explanations in the work. A medical student who values cleanliness and safety above all else. [He appears as a graduate student from the Forest Fire volume onwards.] He has a prickly personality but is actually quite cowardly and suffers from severe mysophobia (germaphobia). In the Virus volume, he had a phobia of blood but is said to have overcome it. He first appeared as a medical student doing volunteer work in the jungle, and from the Human Body volume onwards, he appears as Dr. Brain's assistant. He still has a slight aversion to blood.