Alice

Encyclopedia Entry:
A type of Succubus that has the form of a very young girl. They're a race that arose from sudden mutation, so there are very few of them in existence. It is extremely rare to encounter one. While they are Succubus type monsters, their bodies are always in a “virginal” state. They have almost no knowledge about sex, and they aren’t even aware that men’s mana is what they feed on. For that reason, even though they are a kind of Succubus, they never attack humans. Their disposition is that of a very young human girl, or one even more pure, and more meek.

Guided by the instinct of the Succubi, they appear and seek out men. As written above, they don‘t attack men. They act sweet just like children, and they just want to play together, but their bodies emit a subtle charm magic. Men who spend a lot of time around them end up assaulting them, offering up mana through sexual intercourse.

What is unique about this is, just after having sex with a man, their body returns to a “virginal” state and they also lose their memory of what happened. However, their body unconsciously remembers the pleasure they received from the man, the taste of mana, the man's weak point, and the sexual techniques acquired during the encounter, and they also won't forget the parts of the conversation they had during sex that weren't directly related to sex. (For example suppose a man told an Alice “I love you" during sex, even after the deed is done and she goes back to being a virgin, she'll still remember it, and she'll insist “me and onii-chan are lovers.”)

And then, each time they have sex, due to their memory, their body will rapidly grow sensitive to pleasure. Naturally, their body will use the techniques learned, and they'll be able to milk even more mana out of the man.

Their feelings towards the man will rapidly build up, and as for their “virginity”, at first they'll purely feel that they want to offer their virginity to the man, but then it will rapidly change into something wildly obscene. And then, they grow into even more powerful Succubi, releasing even more powerful charm magic, and possessing superior techniques for pleasing men, while at the same time eternally remaining a pure, innocent little girl.

As was the case with the original type of Succubus, men who continue to copulate with them will end up turning into “Incubi”. Unlike the Succubus, the Alice will not capture her man or take him off to a Mamono realm. However, men who become Incubi are already obsessed with them. Protecting them, and giving them mana, will become their most important tasks.

On a different note, for some reason they like rabbits. When they spot a Wererabbit busily hopping around, they'll chase after her. Generally the Wererabbit will notice along the way, and end up playing with the Alice. This behavior can be seen in every Alice, but the reason for it is still not completely understood.

From Wonderland article:
Normally, Alices can't get pregnant. Also, Alices who spend a long time in Wonderland start to change. Their memories will remain after sex, and they become able to get pregnant. Furthermore, the memories of an Alice's previous sexual encounters with her husband will be restored. These changes are permanent, even if the Alice leaves Wonderland again.

Trivia:

 * This Mamono is based off of the main character in the story Alice in Wonderland.