Algol

"Gol! gol, gol!" (I've told you so many times— I am your Guardian Angel!)

A mysterious creature that claims to be an angel, resembling a winged hamster.
Its lifespan is unknown.
Upon arriving on Earth, it first collided with Sakurai Sora and transferred the "Temporary Magnetic Pattern Linkage" (TMPL, commonly known as the "Template Constitution") to him, allowing itself to live in peace.
Only the protagonist, Sakurai Sora, can hear its voice.

Affiliation: Perseus Constellation
Height: 15cm
Birthday: ???
Likes: Domestically produced feed pellets, naps
Dislikes: Yellow-and-black striped mice, hamster wheels

From Steam