From Viz:
Elegance is a way of life at Ohtori Academy. For close to one hundred years, the elite boarding school has values tradition and ceremony above almost everything else.
Into this academic milieu walks Utena Tnjou, a short-stressed teenaged girl who favors trim-cut boys clothing. Almost immediately, she finds herself embroiled in sword duels, knotty romantic entanglements and a string of shady alliances. There's a cloud of mystery hanging over the campus of Ohtori and everyone Utena meets harbors a dark and twisted secret.