Beast Exorcist Utea, Soul 1: Karen's Flowers

Magical girls Karen and Mitsuki's fight to protect the world and their friends begins here!
Karen, AKA Utea Charm and Mitsuki, AKA Utea Grace, made a contract with a mysterious creature named Kurio.
Now it's their duty to fight monsters and keep the world safe!

One day a beast appears at their school, and they're forced to transform in order to defeat it.
But things don't go so well, and Mitsuki is caught in the creature's tentacled grasp...
Enraged, Karen destroys the monster with her special move, but the pair is flung into an unknown dimension.
There, Mitsuki is once again assaulted by the same monster, and subjected to innumerable humiliations...
Kurio tells Karen there's only one way to save her friend... by giving herself over to the beast instead...

* This work was originally published in Comic Unreal Vol. 48.