Shoujo Senki Soul Eater

Ryuusuke is about to kidnap Kimaira, but his older sister Misa, saves him in an exchange for herself. He decides to rescue Misa, seeks out helpers, and meets Mikoto. She is also attacked by Kimaira and has lost her family. At that very moment, Byakko appears and attacks Mikoto. Mikoto transforms into a Soul Eater and fights against it. But she loses and is raped.
Ryuusuke is devastated by what happens in front of him, but Mikoto decides to take revenge….