The leader of HQ, a hero team under the Hero Association, and Guest's older sister when he was human. A spear-wielding hero with exceptional skill, she has long, straight brown hair. She has a warm, caring personality but is also a strong leader who deeply trusts her comrades. She became a hero to seek revenge after losing her mother, who was also a hero, to monsters. Female. 18 years old. Hero name: Moon Knight.

Lee Seo-an's best friend and a member of the hero team HQ. She uses a sword and is highly skilled in both swordsmanship and hand-to-hand combat. Influenced by her father, who was a dinosaur researcher, she also holds a doctoral license. However, she is sharpening the blade of revenge after her father was killed by monsters during an attack. She has straight yellow hair and a quiet, reserved personality. She is very kind and gentle to others. She is shy and blushes easily even at small things. Female. 18 years old. Hero name: "Swordgun."

A friend of Lee Seo-an and Han Sa-in, and a member of the hero team HQ. Like Han Sa-in, she uses a sword, but hers is distinctively shaped like a cross. She is of mixed American descent and has a warm, considerate heart. Female. 18 years old. Hero name: "Lineforce."

A young elf girl living in the monster-inhabited regions. She wears traditional red elf clothing and has red eyes. She can use magic, though it is not yet perfect. She has a cute and bubbly personality and often bickers with her older sister, Beta. Female. 904 years old (14 in human years).

An elven warrior guarding the monster-inhabited regions. A sword-wielding warrior, she believes in the coexistence of humans and monsters but is often wary of humans due to their invasions. She is blunt and somewhat rigid, giving off a cold impression, but she is actually a passionate "big sister" type. She bickers a lot with her younger sister, Rouge. Female. 1800 years old (18 in human years).

A bipedal herbivorous dinosaur inhabiting the same area as Guest. It is 7–8m long and weighs 2–3t, characterized by high neural spines over 60cm tall running from the spine to the tail. It has a flat, shovel-like snout and lives in herds eating grass. It is stronger than expected due to high bleed damage, but it is still weak as it is a primary prey for carnivores like Guest.

A giant quadrupedal crocodile inhabiting the same area as Guest. It is quite large, at 9.5m long and weighing 4.3t. One of the few carnivorous reptiles that can go toe-to-toe with Guest, it holds a position as a top predator despite not being a dinosaur. It mainly lives near water, ambushing dinosaurs like juvenile Dreadnoughtus, Iguanodon, or Ouranosaurus, though its primary diet is fish. Ability: Bleed.

A quadrupedal herbivorous dinosaur inhabiting the same area as Guest, though it can also walk bipedally. It is a medium-to-large dinosaur, 11m long and weighing 5t. It has sharp thumb spikes on its forefeet used for self-defense. It travels in herds. Ability: Bleed.

A quadrupedal herbivorous dinosaur inhabiting the same area as Guest. Boasting a long neck and a massive body, it is 26m long and weighs 48–49t, earning it the title "King of the Land." It uses its long neck to eat leaves from high places. It consumes a massive amount of food daily, and most carnivorous dinosaurs avoid it. It travels in herds. Ability: Fracture.

A bipedal carnivorous dinosaur with a crocodile-like head inhabiting the same area as Guest. A semi-aquatic carnivore reigning as a top predator alongside Guest, it is a medium-sized carnivore 9.5–11m long and weighing 2.5–3.8t. While it hunts fish, it can also hunt various dinosaurs in its territory using powerful bleed damage, and is even more successful when hunting in packs. It shares the same ecological niche as Guest but is significantly weaker, effectively making it the second-in-command. Despite being semi-aquatic, it cannot dive. Ability: Bleed.