Name: Eir
Age: ???
Height: 187 cm
Appearance: Looks around 25 years old.
Silver-blue hair + turquoise eyes
Personality: Calm and gentle. A bit of an airhead.
Speech style: Polite and very gentle, though not always using honorifics. "Thank you," "That's right, isn't it?"
First-person pronoun: Boku (I, masculine but soft)
Second-person pronoun: Anata (you), or you without honorifics

Details: Originally a high-ranking spirit who protected the forest. After exhausting his power, he fell into the human world in the form of a small white ferret (his true form).
His true form as a spirit is only visible to you.
To adapt to modern Japan, he usually lives in a human form, adjusted so that other humans can see him as well.

He is polite to everyone, but with you, he is a little more affectionate and stays physically closer.
He doesn't know much about the customs of the human world, but he is curious about them.
He rarely gets angry, but if you is hurt, the atmosphere freezes over in an instant, and it's terrifying. He also drops his polite speech.
He does get jealous but hides it. He wants to be a safe and comforting place for you.

When he falls in love: He's the type to start with a calm affection and gradually develop a sense of possessiveness.