Despite the less-than-subtle ecchi nature of the anime,
Ikkitosen (Japanese name) is actually great fun, and has a great storyline - it balances comedy and action (and fanservice, I guess) very well.
All the characters are lively, though there are the couple of obligatory silent characters who let their ass-kicking do the talking. The protagonist, Hakafu, is really naive, and sometimes you do wonder how on earth is this girl the lead in an all fighting anime - but all is revealed....after a plethora of panty shots, of course!
If you like this,
Tengho Tenge is a must - in fact, it's way better!
edit: damn, too slow, sleepy got in before me. Anyway, if you have it order, you're going to end up watching it anyway!