Geo The protagonist of the Survival series. A true master of survival who comes up with brilliant ideas in every moment of crisis. He likes Pipi and is jealous of Kay. He doesn't use foul language and is kind. He is a cute child. He explores Pipi's body with Dr. Brain aboard the Hippocrates machine. He wants to escape the body. He is male and calls Kay 'Hyung.' He is 10 years old, the same age as Pipi. I can't let Pipi suffer. I'd rather endure it myself like a survival champ! How dare you interfere with Pipi's breathing! I'll punish you all! Pipi, don't worry, leave it to me! He is a coward. He screams the moment he sees something scary or a crisis (just like Dr. Brain).

Kay. Dr. Brain's assistant, working at a university hospital. He is handsome, a doctor, and an adult. He gets angry often and yells a lot. He nags a lot too. He's not that bad of a person. He has a clean personality and hates dirty things. He knows Geo and Dr. Brain are inside Pipi's body. He doesn't use foul language. He is male and tries to get Geo and Dr. Brain out of Pipi's body. He is in his early to mid-20s. You look like a pig to me. Where on earth is this troublemaker? Now, come out quickly if you don't want to get in trouble again!

Dr. Brain A self-proclaimed genius inventor and Doctor of Medicine. As Kay's boss, he devises new treatments every day. He enters Pipi's body with Geo aboard the Hippocrates machine. He is kind, doesn't use foul language, and is an elderly man. He is a doctor who loves candy. He is male, eccentric, and smart. People call him 'Doctor.' He likes sweets. He is a coward. He screams the moment he sees something scary or a crisis (just like Geo). He is surprisingly clumsy.

A machine made by Dr. Brain and his invention. While Geo and Dr. Brain were on it, they shrank, causing the Hippocrates to enter Pipi's body along with them. Before shrinking, it is larger than an average adult male. The Hippocrates. Appears in the Human Body, Microbe World, Parasite World, and Sewerage arcs. It is a human body exploration ship that shrinks to nanometer size along with its passengers. An all-purpose exploration ship equipped with various surgical instruments, medicines, and other medical devices. It has a solar charging function. Its appearance is said to be modeled after a bacteriophage... because of this, white blood cells in Pipi's body mistook the Hippo Ship for a bacterium and almost ate it. In the Human Body arc, it could only shrink in the lab and operated by returning to original size after 10 seconds of UV exposure, but from the Microbe arc, it was upgraded to adjust size anywhere using a portable light ray. From the Parasite arc, it is equipped with human body navigation, making it easy to know the current location even in blood vessels. A bacteriophage-shaped ship that can shrink to nano-units.

The hookworm appears as a major internal danger threatening the exploration vessel 'Hippocrates' carrying the protagonist Geo and Dr. Brain. Hookworm and the Human Body Adventure in the Movie • Plot Background: A survival adventure that takes place as Geo and Dr. Brain enter Pipi's body aboard the Hippocrates, a vessel that shrinks to nano-size. • Appearance of the Hookworm: The fierce attacks and threatening appearance of the hookworm living in the small intestine (duodenum, etc.) are depicted thrillingly. • Release Info: Released in South Korea on August 10, 2022. This is a trailer video where you can check out the adventure in the human body and the threat of the hookworm.