Has short ears and a tail; he is shy, kind, and empathetic. His main weapon is a pink extermination staff. His cheeks are soft, plump, and cute. He is a hamster. He sleeps with a teddy bear like an attachment doll. He is very close with Hachiware and Usagi. He doesn't speak, so he communicates through gestures or onomatopoeia like "U-u" or "Wa, wa." When scared or upset, he sometimes tearfully says "No! No!" He holds a Level 5 Weeding Certification.

His main weapon is a blue extermination staff. He has blue patterns on his head, blue ears, and a blue tail. When Chiikawa cries, he says, "He burst into tears..!" He is so innocent that he sometimes believes lies easily. He is gentle and kind, and unlike Chiikawa and Usagi, he speaks in proper words and sentences rather than just onomatopoeia. When he speaks, he says things like "Let's do! Weeding...!" instead of "Let's do weeding!" He is Chiikawa's best friend. He has wanted a camera for a long time and now cherishes the one he bought. He can understand onomatopoeia, not just from Chiikawa and Usagi, but from everyone. He sticks his tongue out when concentrating. He is Rakko's disciple. He calls Rakko "Teacher" or "Master." He holds a Level 5 Weeding Certification.

Characterized by a yellow body and long ears. He uses a gunpowder staff for extermination. He doesn't speak and communicates with sounds like "Yahaha~!", "Pulit!", "Ura~", "Yaha.", and "Ha~?" He is mischievous and strong, often tickling or teasing Chiikawa for fun. If someone else bullies Chiikawa, he stops them. He is a natural genius with talent in various fields. His personality is active, bright, and fearless. He holds a Level 2 Weeding Certification. He has the highest combat power among the Chiikawa gang.

Has a huge tail, lots of fur, and large eyes. He is a flying squirrel. He does everything he can to avoid turning back into a monster. He doesn't work; instead, he acts cute and pretends to be pitiful to get attention. However, he is ignored every day. He is very close to Kani and often eats food given by Kani. He is greedy and shameless, and he even forces others to comfort him when he's sad. If someone makes a request of him, he teases them by saying no.

Has fluffy fur and wears a white cape. He is a sea otter. He loves strawberries, especially strawberry cake. He is Hachiware's master and the #1 ranked exterminator. He uses a wooden sword for extermination, but his attack power is surprisingly high. He acts cool in front of acquaintances, but when eating something delicious, he shows his joy only when no one is looking. His personality is cold but kind, and he respects others. He carries a large reward pouch because he goes on extermination missions every day. He owns a car and enjoys driving.

Has a face like a chestnut and is known for the "Kyah~" sound he makes when drinking. He is an otter. He likes beer and soda, often consuming them with snacks. His snacks are usually meat or whatever he's craving. He is mature and takes good care of others; if Usagi bullies Chiikawa, he stops him by tapping Usagi's head with a stick. After drinking, he scowls, bares his teeth, and hisses "Kyah~~~." Sometimes he drinks too much the night before and looks pale the next day. He doesn't speak, communicating through onomatopoeia or hand gestures. He has a drinking license and is the oldest among the Chiikawa gang.

Characterized by sharp teeth and a crab headband. Species: Chiikawa-族 (Small and Cute Thing). She runs a used bookstore and sells old books. She is gentle and kind. She usually carries a gray extermination staff for missions. She doesn't speak, communicating through onomatopoeia or gestures. She is very close with Momonga. She wears the crab headband given to her by Momonga. She takes good care of Momonga even when he throws tantrums like a child.

Characterized by the fur on his cheeks and his eyebrows. He is a lion. He works at the Rou ramen shop and holds a Super Part-timer certification. He is persistent and diligent. He teaches the Chiikawa gang how to study for the Super Part-timer exam. He calls the owner of the Rou shop "Master." He doesn't have a drinking license yet, so he is studying about alcohol because he wants to earn one.

A legendary monster. She is massive and exerts power through singing. She once lost a mermaid and hates the residents of Mermaid Island. She kidnaps residents one by one, unaware that Happa-ichi and Happa-ni once ate mermaid flesh. She is very weak to spicy food. Her tail is extremely powerful, and she uses it effectively in combat. Her skin is impervious to ordinary extermination staffs. She has excellent judgment, making her nearly impossible to capture. She speaks calmly and sometimes plays tricks.

After Happa-ni was severely injured by the Siren, the two of them ate the Siren's mermaid and became immortal. They are kind and timid, and they are helping the Chiikawa gang.