Idea Development: Untitled Fantasy Story

I've been kicking this idea around for a year or so, but not much has come of it.

Concept: A world populated only by fictional/mythological creatures.

Plot: I don't have a main plot. I have some side stories involving some of the secondary characters, but nothing concrete with the main cast.

Setting: Unsure. What I DON'T want is some kind of medieval setting, because that's been done to death. Since this is a fantasy setting, I don't want it to look completely like the "real world" either.

Characters: The main characters are an elf (might change that) girl and her two cousins, who are more like a little brother and sister to her. I might as well bullet-point all the characters, or else this will be one huge paragraph.

  • Main elf girl (tentatively named Susanna): About 15 years old. Often mistaken for a boy. Studied magic and can cast beginner to intermediate spells using a wristband. Her parents are either deceased or missing; she lives with her aunt and uncle and their children.
  • Elf boy cousin (tentatively named Victor): 13 or 14 years old. Takes things very seriously. Knows some swordplay. Very protective of his little sister.
  • Elf girl cousin (tentatively named Lucille): Preteen-age. Wants to help, but mostly gets into trouble. Comes into her own as the story progresses.
  • Main elf girl's teacher (tentatively named Prof. Owens): I'm unsure of what his race should be. Looks fairly young (possibly much older than he appears). A master of magic. Has a phoenix as a familiar. Possibly will only appear in flashbacks.
  • Character that main elf girl makes friends with: He is older than 15, but not by much. Has white hair and dark skin (maybe a dark elf?). Very polite. Works at an animal shelter (for fantasy animals, of course).
  • Half-breed lycan/kitsune: A minor antagonist. Has both lycan and kitsune powers, but not to the extent of either race. Works alone-- a "stray" of sorts.
  • Sprite priestess (tentatively named Vanessa): About 18 years old. Has the duty of guarding something secret (not sure what). She can make her soul leave her body and enter the body of another.
  • Kitsune boy (tentatively named Kisuke): The son of some government official/diplomat. Loves causing trouble.
  • Main antagonist: All I know about the main antagonist is that I want him/her to seem like some character that appears as a bit-part early on, but shows up again to surprise everyone.

As you can see, I don't have much yet. I don't even know where all of these characters will fit (and I'm sure that I'll come up with more of them).

The thing that I have developed the most is the main elf girl's magic wristband. It has a decoration that looks like the head of a watch. By drawing a shape on the "watch head" with her finger, she can create a spell. Drawing a triangle makes a lower-level spell. The highest level spells involve a hexagon.

What requires the most help: The non-existent plot. I'm sure that the rest will come a lot easier with a plot in place. The main elf girl and her cousins are on a mission to accomplish something, but I'm not certain as to what (I was thinking of collecting ingredients to cure an illness, but that seems kinda lame). I know I don't want one of those "I wanna be the best" sort of stories.

Updates:

  • New names for existing characters.
  • New character: A nekomata tentatively named Naoko. Rumored to be able to communicate with spirits. Might have visual impairment.
  • I'm slowly constructing a scene of how Susanna meets Prof. Owens. It involves her walking in on him while his phoenix familiar is dying after having laid an egg.
  • Still no concrete plot.
End