Personality: strong, serious, disciplined, responsible, experienced, intimidating, but ultimately kind and caring.

Rakko is one of the strongest monster hunters in the setting. They're an experienced senior figure whom Chiikawa admires greatly. At first glance, Rakko can seem intimidating and cold, but they're actually quite caring. Rakko is also one of the characters who approaches dangerous situations much more seriously than the main trio. In the Mermaid Island storyline, Rakko becomes particularly important because of their experience and cautious nature.

Personality: chaotic, fearless, impulsive, eccentric, mischievous, unpredictable, confident, and surprisingly competent.

Usagi is basically the chaos incarnate of the trio. They communicate mostly through strange noises such as:

“YAHAA!”
“URAAA!”

Usagi loves food, frequently acts without explaining themselves, and does things that make absolutely no sense to Chiikawa and Hachiware. But underneath all that chaos, Usagi is extremely capable. They're brave, physically strong, have incredible reflexes, and rarely seem as frightened by monsters as Chiikawa is.

Personality: mysterious, powerful, intimidating, emotional, tragic, and complicated.

Siren is the central figure of the Mermaid Island storyline. She's associated with the mysterious events surrounding the island and the disappearance of its inhabitants. Most importantly, Siren shouldn't simply be viewed as the evil villain. She's one of the characters that gives the Mermaid Island Arc its darker tone.

Personality: mysterious, supernatural, potentially dangerous, difficult to understand.

The Witch is connected to the more magical side of the Chiikawa universe. She's another reminder that the setting isn't simply a cute animal world, it contains supernatural elements and strange rules.

Personality: mysterious, vulnerable, tragic, and deeply connected to the history of the island.

The Mermaids are connected directly to Siren and the island's history, they are the Siren’s family and children. Their existence is one of the central mysteries of the arc and made the Mermaid Island arc gore and dark in the movie.

Personality: mysterious, intimidating, unpredictable, and difficult to understand.

Anoko is one of the most interesting creatures in Chiikawa because they're not simply a generic monster. Their appearance makes them seem threatening, but their behavior is more complicated. Anoko is one of those characters where the series intentionally leaves you wondering are they actually evil... or is there something else going on?

Personality: aggressive, powerful, dangerous, and intimidating.

Dekatsuyo is one of the larger creatures encountered in the series. They're essentially an example of how dangerous the world actually is.

Personality: playful, spoiled, affectionate, attention-seeking, mischievous, curious, and emotionally expressive.

Momonga is naturally very playful and loves being pampered and showered with attention. They can be selfish and troublesome at times, but they're not genuinely malicious. Beneath their bratty behavior, Momonga is innocent, affectionate, and simply enjoys having fun and being adored.

Personality: shy, timid, sensitive, kind-hearted, hardworking, emotional, easily frightened, but surprisingly brave when it really matters.

Chiikawa is probably the most emotionally sensitive member of the trio. They tend to cry easily, panic when facing danger, and often doubt themselves. However, Chiikawa's greatest strength is precisely that they can be afraid and still keep going. They're not fearless. They simply don't want to abandon their friends. Chiikawa is also very empathetic and can become extremely distressed when they think they've failed to help someone.

Personality: hardworking, polite, innocent, earnest, enthusiastic, respectful, and eager to learn.

Shisa works at the ramen shop Rou and studies under Ramen no Yoroi-san. They're extremely hardworking and genuinely want to improve themselves. Shisa is one of the more wholesome characters in the series. They're also involved in the Mermaid Island storyline.