A Kaiju Hunter. He is a male white cat Yaya. His full name is Merong White. He is positive, an 'F' type (feeling-oriented), very open to outsiders, and energetic. However, he shows an otaku side, being a fan of J-POP. He can understand what Violet is saying. He has plus signs (+) in his pupils. His weapons include a Kaiju Vacuum and a Kaiju Analyzer (which analyzes weaknesses and deploys support drones).

A Kaiju Hunter. He is a male black cat Yaya. His full name is Merong Black. He is negative and displays very 'T' type (thinking-oriented/factual) behavior. He has a tsundere personality, helping others while being blunt about his feelings. He is calm and enjoys songs with a trot vibe. He has minus signs (-) in his pupils. His weapon is a ray gun.

A Kaiju Hunter. She is a female purple cat Yaya. She wears a purple scarf and purple gloves shaped like cat paws during combat. She does not speak (expressing herself through actions instead because she has a complex about her voice). She is an excellent fighter. While she may seem cold and similar to Black on the outside, she is a warm and friendly 'big sister' type at heart. She loves cute things. She is very similar to White and has division signs (÷) in her pupils. She is fond of Sadong-i.

A Kaiju Hunter. He is a young male mint-colored cat Yaya. His full name is Merong Mint. He admires Merong White and calls him 'sunbae'. He even wears a mask of Merong White's face during battle. He has a bit of a 'madness' streak. He and Merong Pink are known as the Cutie Merong Hunter Duo. He has less-than signs (<) in his pupils. He serves as support and uses a sword as his weapon.

A Kaiju Hunter. She is a young female pink cat Yaya. Her full name is Merong Pink. She admires Merong Black and calls him 'sunbae'. She even wears a mask of Merong Black's face during battle. She has a bit of a 'madness' streak. She and Merong Mint are known as the Cutie Merong Hunter Duo. She has greater-than signs (>) in her pupils. She serves as support.

A Kaiju Hunter and a male cat Yaya (presumably). He is the boss of Merong Black, White, and Violet, and assigns them missions. He always gives orders through a mascot costume that looks like himself. His full name is presumably Merong Original. He is the most mysterious character with the least information available. Very suspicious.

A member of the Yaya race. He is Yako's younger cousin.

A member of the Yaya race and a YouTuber. He is Sadong-i's older cousin. He is bald.

A member of the Yaya race. She is Yako's mother.

A member of the Yaya race and Yako's friend. He is highly intelligent and a scientist. He came from the future. He is currently collaborating with the Kaiju Hunters. He gives out a lot of spoilers.