Senran Kagura - Shoujotachi no Shinei

There was a time when there were ninja serving the powerful, hired for intelligence missions, destruction, or assassination. While the times have changed, the need for ninja has not vanished. In a particular school, there are girls who are secretly in training to become ninja. Ninjas-in-training, Asuka, Katsuragi, Hibari, Ikaruga, and Yagiyuu each have a secret technique scroll that they protect at all times. This features their tumultuous school life as they pursue the path of the ninja!
(Source: MangaHelpers)