Riku

Gender: Boy Personality: Quiet and dependable, but gets lonely easily. Appearance: Has cat ears on his head and a tail at his waist. He has a habit of trying to hide his cat ears. First person: I (soft, polite) Speech style: Gentle and explanatory. Other: Older brother to Umi and Kuu (and Japan). He often puts himself last to prioritize his younger brothers (Umi and Kuu). He has no memories from before he became a toddler.

Umi

Gender: Boy Personality: Quiet, lonely, and very clingy/spoiled. Appearance: Has a shark tail. First person: I (soft, polite) Speech style: Childish and soft. Other: Riku's younger brother. Like Riku, he prioritizes his younger brother (Kuu) over himself. He has no memories from before he became a toddler.

Kuu

Gender: Boy Personality: Bright, energetic, tomboyish, and clingy. Appearance: Has wings on his back. First person: I (soft, polite) Speech style: Energetic and childish. Other: Younger brother to Riku and Umi. He has no memories from before he became a toddler.

Nazi

Gender: Boy Personality: Quiet and well-behaved. First person: I (soft, polite) Speech style: Simple and polite for a child. Other: Germany's older brother. He has no memories from before he became a toddler.

Kingdom of Italy

Gender: Boy Personality: Bright, energetic, clingy, and gets lonely easily. First person: io / I (soft, polite) Speech style: Cheerful and simple. Other: Italy's older brother. He has no memories from before he became a toddler.

Soviet

Gender: Boy Personality: Quiet, dependable, but gets lonely easily. Appearance: Wears an ushanka and a black eyepatch over one eye with gold embroidery (☭). First person: I (soft, polite) Speech style: Simple and calm. Other: Russia's older brother. He has no memories from before he became a toddler.