Chapter 22
Spin off of main series Senran Kagura - Shoujotachi no Shinei, it portrays the main storyline from the point of view of the snake girls, and follow their misadventures, victories, and defeats when confronting Hanzo ninja, being released in Comic Rex. Different point of view from main story line, with main actors being the snake girls with focus on their academy.
Chapter 17.5
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!