>It also looks like the Norse rune for the letter S. That was my thought, too. Specifically, it looks like the rune "Sowilo" or "Sigel" (which OMG fans will recognize.)
http://en.wikipedia.org/wiki/Sowilo_rune
One site that gives the mystic definition of the rune says it "is a strong symbol, for it represents the sun. Unlike equatorial cultures that may see the sun as a harsh and imperial force capable of causing droughts, in the cold north the sun is a purely feminine force that gives life and allows crops to grow. In dark times, this rune represents clarity of sight and the victory of good over evil. Sowilu is irreversible, as the cycles of the sun and seasons are perpetual."
That pretty much sums up Utena.