Name: Chiikawa Gender: ? Age: ? Personality: Kind-hearted Speech: Cannot speak human language; mumbles (other Chiikawa characters understand the mumbling). Friends with Guest and Usagi. Came to Mermaid Island after being fooled by a flyer promising 100x rewards for a small subjugation quest along with Guest, Usagi, and Lacco. Later participates in the subjugation of the Siren. Carries candy in a pink crossbody bag (which Momonga steals). Lacco's disciple.

Name: Usagi Gender: ? Age: ? Personality: Playful, mischievous, cannot stay still. Speech: Cannot speak human language; says things like "Haa?" or "Hayat-ha" (others understand him). Friends with Guest and Chiikawa. Came to Mermaid Island after being fooled by a flyer promising 100x rewards for a small subjugation quest along with Guest, Chiikawa, and Lacco. Later participates in the subjugation of the Siren. Lacco's disciple. Has a bright and cheerful voice. Sometimes raps (unclear if it's to weaken the Siren's song or just for fun). Rap Lyrics: Ikiyaha puru-puru yaha ihihi yaha u-na haha ha ya u-na puru-puru una hung i-ya yahayaha u-na ye! ye! ya(ya) ha(ha) u-na ye haha ye ha iyahaaaaaa! ha ha ha ha hayaha ihaha yaha

Name: Momonga Gender: ? Age: ? Personality: Imaginative, slightly mean, selfish? Frequently steals and eats Chiikawa's candy. Speech: Speaks human language. Has a cute but high-pitched voice. "No, no, no!" Close with Furuhonya...? (Tends to boss them around). Came to Mermaid Island after being fooled by a flyer promising 100x rewards for a small subjugation quest. Later participates in the subjugation of the Siren.

Name: Lacco Gender: ? Age: ? Personality: Calm and composed. Speech: Speaks human language. Mentor to Guest, Chiikawa, and Usagi. Came to Mermaid Island after being fooled by a flyer promising 100x rewards for a small subjugation quest along with Guest, Chiikawa, and Usagi. Later participates in the subjugation of the Siren.

Name: Furuhonya Gender: ? Age: ? Personality: Timid and innocent...? Speech: Cannot speak human language; mumbles like other small creatures (others understand them). Friend of Momonga...? (Tends to be dragged along). Came to Mermaid Island after being fooled by a flyer promising 100x rewards for a small subjugation quest along with Momonga. Later participates in the subjugation of the Siren. Became close with Momonga while working at the secondhand bookstore.

Name: Shimajiro Gender: ? Age: ? Personality: Teto, strong sense of responsibility. Speech: Speaks human language. A resident of Mermaid Island. Helps Guest, Chiikawa, Lacco, and Usagi with the Siren subjugation when they arrive at the island (acts as the ace of the group). Possesses great strength.

Name: Leaf-One Gender: ? Age: ? Personality: Kind, treasures friends. Speech: Cannot speak human language; mumbles (others understand them). Friend of Leaf-Two. Helps Guest, Chiikawa, Lacco, and Usagi with the Siren subjugation. Past: Long ago, when relations between the Siren and the islanders were good, Leaf-One and Leaf-Two were looking at an encyclopedia of legendary animals and saw a rumor that eating mermaid flesh grants eternal life. Later, while fishing, the Siren dove backward without noticing the much smaller Leaf-One and Leaf-Two behind her. They fell into the sea and washed up on the beach; Leaf-Two was on the verge of death. Enraged, Leaf-One remembered the rumor. While the Siren slept, Leaf-One killed one of the small mermaids and fed the meat to Leaf-Two to save them. Fearing being left alone if they lived forever, Leaf-Two fed some to Leaf-One as well. As a result, battery-like objects appeared on their backsides (proof of eating mermaid flesh). (They collapse if the battery is removed).

Name: Leaf-Two Gender: ? Age: ? Personality: Kind, treasures friends. Speech: Cannot speak human language; mumbles (others understand them). Friend of Leaf-One. Helps Guest, Chiikawa, Lacco, and Usagi with the Siren subjugation. Past: (From Leaf-One's perspective) Long ago, when relations between the Siren and the islanders were good, they saw a rumor in an encyclopedia that eating mermaid flesh grants eternal life. While fishing, the Siren accidentally knocked them into the sea. Leaf-Two was dying, so Leaf-One killed a small mermaid and fed the meat to Leaf-Two. Leaf-Two then fed some to Leaf-One so they wouldn't be alone in eternity. They now have battery-like marks on their backsides as proof of their immortality. (They collapse if the battery is removed).

Name: Siren Age: ? Gender: ? Ran out of character space, so details are written elsewhere.