Name: Kei Gender: Male Age: Early to mid-20s Occupation: Medical Student -> Graduate Student Appearance: Yellow hair tied low with dark green eyes Traits: Severe mysophobia. He is the sub-protagonist.

Name: Geo Gender: Male Age: Early teens Height: 150cm Appearance: Navy hair with black sanpaku eyes Traits: Has incredible stamina for an elementary student. He is the protagonist.

Name: Pipi Gender: Female Age: Early teens Height: 150cm Nickname: Jungle Girl Appearance: Red hair with black sanpaku eyes Traits: A glutton. She eats a massive amount.

Name: Dr. Adie Gender: Female Age: Mid to late 20s Appearance: Brown hair with black eyes (freckles on both cheeks) Traits: A doctor at a tropical disease research center in the African wilderness. She was Dr. Brain's student, and is Kei's university senior as well as his first love.

Name: ? Gender: Female Age: ? Appearance: Red hair with dark gray eyes Traits: Unlike Pipi, her skin is fair rather than dark.

Name: Dr. Brain Gender: Male Appearance: White hair with sanpaku eyes Traits: Just an ordinary doctor.

Name: Kenji Gender: Male Appearance: Dark light-brown hair with dark light-brown eyes Traits: Appeared in the Abnormal Climate and High-Rise Building survival series; Geo's group saved him when he was on the verge of death from heatstroke. He is a Japanese boy.

Name: Seo Dong-gyeong Gender: Female Occupation: Cellist Appearance: Long yellow hair with dark gray eyes Traits: While Pipi was originally the main heroine of the Geo series, she appeared as the main heroine instead of Pipi in High-Rise Building and Abnormal Climate. She is often seen with Kenji, frequently drawn in the same panels.