AomiaWech says:

This is my favorite hentai anime. I watched it countless times >_>
When I first started watching, Reiya was my favorite. She is blonde and looked very attractive with her bule & black outfit. Her experiences particularly during “Ikusa otome valkyrie shinshou” made me felt sympethy and strong affection toward her. But as I repeat watching this series over the times. I find my self to love Aliya even more. I think its because of her unbending character.
—> So who is your favorite female protagonist?

I like this particular genre. I have watched many similiar titles but Ikusa otome series are in my opinion the best. If you are looking for similar animes. I would like to put down some suggestions below.

Hell Knight Ingrid
Soukou Kijo Iris (Armored Knight Iris)
Himekishi Angelica
Hime Dorei
Dark Chapel
Rei Zero
Space Pirate Sara (Uchuu Kaizoku Sara)
Himekishi Lilia (Princess Knight Lilia)
Kuroinu: Kedakaki Seijo wa Hakudaku ni Somaru
Shoujo Senki Brain Jacker
Koukai Benjo The Animation
Elf Hime Nina

3D
Mai Shiranui – Sonata of Disgrace (Mai Ryona Ryoujoku no Rondo)
The Bound Minuet – War Princess of Exquisite Shame (Touki Reijoku – Kinbaku no Menuet)
The Bound Marionette – War Princess of Exquisite Shame (Touki Reijoku – Kinbaku no Marionettet)
Sophia labyrinth