favorite female ninjas?
 

Mai isn;t fewmale Ninja.

Kasumi, Ayane from DOA3
Psylocke from X-Men Legends, X-Men New Dimension
Kunimitsu from Tekken 2, Tekken Tag Tournament
Taki from Soul Blade, SoulCalibur 3
that's all I can think of at the moment.

Oh yeah, i kick ass with Kasumi =P

Don't ninjutsu style fighters get called ninjas cos most of the moves are somersaults and flips, moving fast, gliding moves, using weapons while moving or attacking.
Kasumi is a pretty simple character to use and once you are more familar with all of her attacks, I start to learn counterattacks so I catch the enemy's attack.
I like Taki's move when she rolls and rise attacks and is in the air and kick while in the air, it's pretty going it's like same dunking the enemy.
Kunimitsu is a good character to use, some moves are similar to Yoshimitsu's except she uses a dagger, it's a shame that she hasn't been in the latest games of Tekken cos in Tekken Tag she has a grab where she climbs the person at grabs the head with her legs and flips the enemy which is similar to a frankenstiener or a hurracana.

Kitana is good.

The girl from "Red Ninja" and Nika from Guild Wars: Factions

I like Taki too, she´s good fighter. :D And Mai is a ninja as I know.

Taki is interesting cos when I look at Soul Blade compared to SoulCalibur3 she has changed a bit using magic, more moves that she can do, my favourite grab is the trampoline jump another one is when she flips backwards while flipping the enemy like Northern Lights Suplex.