|Occupation:||Student at Mugen Academy|
|Associates:||Gallica, Damask, Centi, Alba|
|First Appearance:||Mugen Gakuen - Mistress Labyrinth|
Moss was a musical-only character who appeared in Mugen Gakuen - Mistress Labyrinth and its revision. She was one of the only people from the planet Grimm to survive the Death Busters' attack on that planet, and fled with Gallica and his family to Earth.
While on Earth, she disguised herself as Seika Hoshino (星野聖火), a student at Mugen Academy. At the end of both musicals, she was revealed to be in fact the last princess of Grimm, which was why Gallica had adopted her and claimed she was his daughter.
- The surname she used on Earth, "Hoshino," is a pun similar to that in the surnames of the Sailor Senshi; the "no" (野) literally means "field" but is pronounced the same as the word meaning "of" (の), making her name sound like it means "of the star." Her given name means "sacred fire."