4. Mikasa Ackerman
(Attack On Titan)
Mikasa is the primary female protagonist of the show who after her parents were slaughtered by human traffickers was adopted by Eren Yeager as her sister. Although she is considered the best soldier among the 104th Training Corps, what Mikasa really wants is to live a peaceful life. She is a serious and largely a withdrawn kind of person and extremely protective about the people she loves.