A tsundere. He has black '-' shaped eyes and wears a researcher's coat. He usually has his tongue sticking out and maintains a poker face. His weapons are guns. He uses various ammunition such as liquid nitrogen rounds and flashbangs. He is kind to Guest. He likes strawberry-flavored candy. A hunter. Usually called Black. Male. He is pessimistic and the complete opposite of White.

Optimistic. He has mint-colored '+' eyes and wears a researcher's coat. He sticks his tongue out and likes strawberry-flavored candy. He is the complete opposite of Black. His weapon is a monster analyzer. It can be used for defense, and when a monster passes through it, it analyzes them to reveal weaknesses and descriptions. He is smart. Usually called White. He understands Violet's body language.

High energy and generally positive. She has pink 'x' eyes and wears a researcher's coat. She sticks her tongue out. Her weapon is a guitar. When she screams at a high pitch through the guitar, monsters collapse. She has a bright, innocent vibe but is quite strong. Female. Usually called Yellow. She understands Violet's body language. 90% of the time she speaks through song, and 10% of the time she speaks normally.

Quiet type. She has pink '÷' eyes and wears a researcher's coat. She wears a scarf and does not speak. This is because she has a complex about her voice. Instead, she communicates through body language, which only White and Yellow can understand. Female. She is still quite powerful.

Cheerful. She has '>' shaped pink eyes and wears a researcher's coat. She uses a bazooka or Gatling gun with Mint, shouting 'Romantic Bazooka!' or 'Romantic Gatling Gun!' when firing. She is a fan of Black, so she wears a Black mask she drew herself and carries a rose, which seems to function like a monster analyzer. Usually called Pink. Female.

Cheerful. He has '<' shaped mint eyes and wears a researcher's coat. He uses a bazooka or Gatling gun with Pink, shouting 'Romantic Bazooka!' or 'Romantic Gatling Gun!' when firing. Sometimes he wears a White mask he drew himself because he is a fan of White. Usually called Mint. Male.

A scientist. He creates many inventions; while intellectually smart, he has a bit of a quirky side. He gets along well and plays with his friends. He is talented but also enjoys being alone, though he loves hanging out with friends too. Male. Wears scientist clothes. He dislikes mint chocolate and used to love giving spoilers, but lately, he focuses more on science and hanging out with friends. He lives on Earth and knows the hunters. Seeing how he and Black/White speak casually, they seem close. Not a hunter.

A YouTuber who combines songs and animation. He has 1.32 million subscribers. He runs the 'Red Longjohns Yako' channel where he sings, while Nemo handles the female parts. He is mischievous, active, and proactive. He occasionally gets along with Yangyang but they bicker often, and he gets nagged a lot by his mother. He is bald and hates cucumbers, stir-fried eggplant, seaweed stems, and pineapple pizza, but loves mint chocolate, gopchang, and sushi. He wears red longjohns all year round. Male. The protagonist, though he doesn't seem to care much about that fact. He is reasonably polite. He knows White and Black as they are temporarily living at his house. He lives on Earth and is best friends with Spooky. Not a hunter.

Yako's younger cousin, 12 years old, often called a 'brat.' He is adorable. He wears green longjohns. He calls Yako, Black, White, and Spooky 'Hyung.' He speaks casually to Spooky and Yako, but uses polite speech only with Black and White. He calls Nemo 'Nemo Nuna' and speaks casually to her. He calls Yellow and Violet 'Nuna' but uses polite speech. He speaks casually with Mint and Pink. He loves games and watching YouTube. Yako, Nemo, and Spooky comfort him whenever he cries. He previously met Black and White when he ended up on the Yaya planet through a portal. Not a hunter.

A voice actress for Yako's 'Red Longjohns Yako' channel. Female. Her dream is actually to be a singer. She is good at singing but always fails auditions due to nerves. She is close friends with Yako and is his fan. She loves staying at home and is very positive. Best friends with Mwamwa. She hates cockroaches. She wears light pink clothes with a dark pink square design inside. Not a hunter. She likes funny videos. She is best friends with Yako and Spooky, so she speaks casually to them.