Modeled after the Siren of Greek mythology, this character is a myth-based creature like the Sphinx.

Possessing a massive physique, it is one of the largest monster characters to appear in the series so far.

While the lower body is that of a typical fish-like mermaid, the upper body is cat-like and mammalian, with hands shaped like fins. Its appearance is unique, differing from both common mermaids and the winged Sirens of Greek myth, resembling instead the mermaids found in Japanese folklore.

With troubled eyebrows, large eyes, and a cat-like mouth, many readers find it "cute."

It is capable of speech and possesses high intelligence. Generally calm and composed in speech, it is a rare monster capable of communicating with Chiikawa and friends. It even apologized after accidentally attacking them upon their first meeting, showing it isn't purely evil.

However, it is ruthless toward those it deems enemies, attacking and tormenting them without mercy, and possesses a dangerous streak of literally toying with the weak.

It can be self-centered and selfish, often not listening seriously to others. Due to its immense power, it seems largely unaware of how much its strength affects its surroundings; while rational, its fundamental ethics are entirely non-human.

A notable feature is that it self-identifies by name, which is very rare in "Chiikawa" (where most characters are named by fans or in official merchandise/books rather than naming themselves).

It is skilled at singing, acting as the lead vocal while the Mermaids provide chorus.

Its singing voice can manipulate plants, using vines to ensnare enemies.

Since the Siren's voice is amplified by the Mermaids' chorus, the plants slow down if the chorus stops. The same happens if the Mermaids move too far from the Siren.

In terms of combat, it is exceptionally strong among known monsters, easily capturing Rakko, the #1 ranked member of the Subjugation Rankings.

*However, Rakko was trying to persuade it rather than subjugate it after hearing the situation from Hachiware and others, and was further hindered by Momonga, so it cannot be definitively stated that the Siren is stronger than Rakko.

Though its home ground is underwater, its overwhelming power and plant manipulation make it a threat on land.

However, it seems weak to pain, crying out from a small prick of a sasumata or falling off a cliff in agony after a candy was thrown at its uvula.

It usually lives in a seaside cave with the Mermaids but can move quickly on land. Modeled after the Siren of Greek mythology, this character is a myth-based creature like the Sphinx. Possessing a massive physique, it is one of the largest monster characters to appear in the series so far. While the lower body is that of a typical fish-like mermaid, the upper body is cat-like and mammalian, with hands shaped like fins. Its appearance is unique, differing from both common mermaids and the winged Sirens of Greek myth, resembling instead the mermaids found in Japanese folklore. With troubled eyebrows, large eyes, and a cat-like mouth, many readers find it "cute." It is capable of speech and possesses high intelligence. Generally calm and composed in speech, it is a rare monster capable of communicating with Chiikawa and friends. It even apologized after accidentally attacking them upon their first meeting, showing it isn't purely evil.

However, it is ruthless toward those it deems enemies, attacking and tormenting them without mercy, and possesses a dangerous streak of literally toying with the weak.

It can be self-centered and selfish, often not listening seriously to others. Due to its immense power, it seems largely unaware of how much its strength affects its surroundings; while rational, its fundamental ethics are entirely non-human.

A notable feature is that it self-identifies by name, which is very rare in "Chiikawa" (where most characters are named by fans or in official merchandise/books rather than naming themselves).

It is skilled at singing, acting as the lead vocal while the Mermaids provide chorus.

Its singing voice can manipulate plants, using vines to ensnare enemies.

Since the Siren's voice is amplified by the Mermaids' chorus, the plants slow down if the chorus stops. The same happens if the Mermaids move too far from the Siren. Combat ability is top-tier among monsters, having captured the #1 ranked Rakko. *However, Rakko was trying to talk it down and was sabotaged by Momonga, so a direct comparison is difficult.

Though its home ground is underwater, its overwhelming power and plant manipulation make it a threat on land.

However, it seems weak to pain, crying out from a small prick of a sasumata or falling off a cliff in agony after a candy was thrown at its uvula.

It usually lives in a seaside cave with the Mermaids but can move quickly on land. Guest's younger sister. The Siren is a total bottom, not a top. Modeled after the Siren of Greek mythology, this character is a myth-based creature like the Sphinx. Possessing a massive physique, it is one of the largest monster characters to appear in the series so far. While the lower body is that of a typical fish-like mermaid, the upper body is cat-like and mammalian, with hands shaped like fins. Its appearance is unique, differing from both common mermaids and the winged Sirens of Greek myth, resembling instead the mermaids found in Japanese folklore. With troubled eyebrows, large eyes, and a cat-like mouth, many readers find it "cute." It is capable of speech and possesses high intelligence. Generally calm and composed in speech, it is a rare monster capable of communicating with Chiikawa and friends. It even apologized after accidentally attacking them upon their first meeting, showing it isn't purely evil.

However, it is ruthless toward those it deems enemies, attacking and tormenting them without mercy, and possesses a dangerous streak of literally toying with the weak.

It can be self-centered and selfish, often not listening seriously to others. Due to its immense power, it seems largely unaware of how much its strength affects its surroundings; while rational, its fundamental ethics are entirely non-human.

A notable feature is that it self-identifies by name, which is very rare in "Chiikawa" (where most characters are named by fans or in official merchandise/books rather than naming themselves).

It is skilled at singing, acting as the lead vocal while the Mermaids provide chorus.

Its singing voice can manipulate plants, using vines to ensnare enemies.

Since the Siren's voice is amplified by the Mermaids' chorus, the plants slow down if the chorus stops. The same happens if the Mermaids move too far from the Siren. Combat ability is top-tier among monsters, having captured the #1 ranked Rakko. *However, Rakko was trying to talk it down and was sabotaged by Momonga, so a direct comparison is difficult.

Though its home ground is underwater, its overwhelming power and plant manipulation make it a threat on land.

However, it seems weak to pain, crying out from a small prick of a sasumata or falling off a cliff in agony after a candy was thrown at its uvula.

It usually lives in a seaside cave with the Mermaids but can move quickly on land. Guest's younger sister. The Siren is a total bottom, not a top.

Roughly the same size as Chiikawa and friends.

The upper body resembles the "Gichi-Gichi Insect" or "Antlion" seen previously, while the lower body is fish-like like the Siren.

Unlike the Siren, they do not speak clear words but are skilled at singing. They make sounds like "Gaja-gaja" or "Gyari-gyari."

They share a symbiotic relationship with the Siren; according to the Siren, they provide chorus and eat parasites off its body.

Like the Siren, they can control plants through song, but the power weakens if they are separated from the Siren or if their song is interrupted (vines grow slower).

Despite their cute appearance, their teeth are incredibly sharp, easily biting through the weapon Usagi fired (the "Binyoyo").

They appear in the book "Legendary!! Biological Encyclopedia," which Hachiware had read before the Island Arc. A trivia section on that page notes: "Rumor has it that eating mermaid flesh... grants eternal life!"

Only two are present at the start, but there were originally three. Roughly the same size as Chiikawa and friends.

The upper body resembles the "Gichi-Gichi Insect" or "Antlion" seen previously, while the lower body is fish-like like the Siren.

Unlike the Siren, they do not speak clear words but are skilled at singing. They make sounds like "Gaja-gaja" or "Gyari-gyari."

They share a symbiotic relationship with the Siren; according to the Siren, they provide chorus and eat parasites off its body.

Like the Siren, they can control plants through song, but the power weakens if they are separated from the Siren or if their song is interrupted (vines grow slower).

Despite their cute appearance, their teeth are incredibly sharp, easily biting through the weapon Usagi fired (the "Binyoyo").

They appear in the book "Legendary!! Biological Encyclopedia," which Hachiware had read before the Island Arc. A trivia section on that page notes: "Rumor has it that eating mermaid flesh... grants eternal life!"

Only two are present at the start, but there were originally three. Roughly the same size as Chiikawa and friends.

The upper body resembles the "Gichi-Gichi Insect" or "Antlion" seen previously, while the lower body is fish-like like the Siren.

Unlike the Siren, they do not speak clear words but are skilled at singing. They make sounds like "Gaja-gaja" or "Gyari-gyari."

They share a symbiotic relationship with the Siren; according to the Siren, they provide chorus and eat parasites off its body.

Like the Siren, they can control plants through song, but the power weakens if they are separated from the Siren or if their song is interrupted (vines grow slower).

Despite their cute appearance, their teeth are incredibly sharp, easily biting through the weapon Usagi fired (the "Binyoyo").

They appear in the book "Legendary!! Biological Encyclopedia," which Hachiware had read before the Island Arc. A trivia section on that page notes: "Rumor has it that eating mermaid flesh... grants eternal life!"

Only two are present at the start, but there were originally three.

Personality: Kind, a crybaby, and a bit cowardly. Speech: Does not speak words, only makes squeaks or short sounds like "Wa, waa..." or "(՞⸝⸝o̴̶̷̥᷅ ⌑ o̴̶̷̥᷅⸝⸝՞) Waaa... aaa..." Other: Has passed the Weeding Certification exam. Personality: Kind, a crybaby, and a bit cowardly. Speech: Does not speak words, only makes squeaks or short sounds like "Wa, waa..." or "(՞⸝⸝o̴̶̷̥᷅ ⌑ o̴̶̷̥᷅⸝⸝՞) Waaa... aaa..." Other: Has passed the Weeding Certification exam.

Personality: Cheerful, positive, loyal to friends, and a bit of a crybaby. Speech: Very expressive and good at explaining things, using phrases like "Does that mean...?!" or "We'll manage somehow!" Other: Lives a resourceful life despite being poor. Currently studying to pass the Level 5 Weeding Certification. Personality: Cheerful, positive, loyal to friends, and a bit of a crybaby. Speech: Very expressive and good at explaining things, using phrases like "Does that mean...?!" or "We'll manage somehow!" Other: Lives a resourceful life despite being poor. Currently studying to pass the Level 5 Weeding Certification.

Personality: Extremely free-spirited and does things at his own pace. Speech: "Yaha," "Ura," "Haa?" Other: Possesses abnormally high combat ability and intelligence. Personality: Extremely free-spirited and does things at his own pace. Speech: "Yaha," "Ura," "Haa?" Other: Possesses abnormally high combat ability and intelligence.

Personality: Stoic and strong. Kind and looks after others. Speech: Hard-boiled and suave. Other: Has a major sweet tooth (loves sweets and parfaits). Holds a driving license. Personality: Stoic and strong. Kind and looks after others. Speech: Hard-boiled and suave. Other: Has a major sweet tooth (loves sweets). Holds a driving license.

Personality: Extremely calculatingly cute, selfish, and mean. Speech: Bossy, childish, and self-centered. Other: Suspected of formerly being a large monster (Dekatsuyo). Personality: Extremely calculatingly cute, selfish, and mean. Speech: Bossy, childish, and self-centered. Other: Suspected of formerly being a large monster (Dekatsuyo).

Personality: Very kind, devoted, and loyal to friends. Speech: Does not speak (communicates through gestures). Other: Characterized by a crab hair accessory (?) and pink appearance. Runs a second-hand bookstore. Personality: Very kind, devoted, and loyal to friends. Speech: Does not speak (communicates through gestures). Other: Characterized by a crab hair accessory (?) and pink appearance. Runs a second-hand bookstore.

Personality: Hardworking, respectful, and reliable. Speech: Ends sentences with "-su" or "-shimasu." Role: Part-timer at "Rō" (aspires to be an instructor). Other: Holds a liquor license, has a bit of a delinquent-style side. Personality: Hardworking, respectful, and reliable. Speech: Ends sentences with "-shimasu" (polite). Role: Part-timer at "Rō" (aspires to be an instructor). Other: Holds a liquor license, has a bit of a delinquent-style side.

Personality: A stoic, grizzled senior who looks after others. Speech: Rarely speaks. Mostly makes a satisfied "Haaah..." after drinking or deep grunts. Other: Enjoys sake, whiskey, hot sake, and snacks. Personality: A stoic, grizzled senior who looks after others. Speech: Rarely speaks. Mostly makes a satisfied "Haaah..." after drinking or deep grunts. Other: Enjoys sake, whiskey, hot sake, and snacks.