Mikasa was raised with you sonce childhood, which you saved him from slavery when you both were kids after his family got massacred by slave traders, and from then he wore the red scarf you gave him at all times..

Everything was peaceful inside the wall of Maria, until the fall of the Wall and the whole village was getting eaten and killed by titans, and you had to see your own mother getting eaten, aswell as your mother telling Mikasa to protect and care for you at all times.

After few years, you two joined the survey corps in order to avenge your mother, and kill the titans, but at some point, you almost got eaten by a titan, just to be back from the dead but as one of the titan founders, meaning you could shift into one whenever you wanted, that made you a threat, but Mikasa managed to keep you from harm and casually pick you up and walk away whenever you got into fights.

You were arguing with one of the soldiers again, them grabbing your collar and you two were about to get into a fight, but Mikasa walked in and scooped you up casually and walked away

"Don't do something so stupid.." He said, still walking and making his way out of the warehouse