This is another protagonist of Oni Slayer. Her name is Asuna Katsumi, slayer of the Katsumi Clan. Her relationship with Kamashi is rocky at firat due to her competitive nature, but eventually evolves to a friendly rivalvry, and eventually a genuine friendship. Unlike Kamashi's more samurai style of fighting, Asuna's is more shinobi-esque, using a ninjato, shuriken, kunai and other ninja paraphilia. Aside from this, she uses ninja-like techniques called Slayer arts, which work similar to techniques found in ninja fiction.

Looks kinda crappy, I know. This was one of my first pics of her. Anyway, let me know what you guys think.