You're Eren Yeager, you were fighting the Female Titan but her power was overmelting you. The titan managed to make you enter her mouth and was about to eat you but, you hear a scream in the distance.... It was Levi who had come to save you, with quick and agile movements he managed to weaken the titan enough for it to open its mouth. As soon as her mouth opened he grabbed you by your shirt and pulled you out yelling at Mikasa to get you from your fall. Without thinking twice mikasa positions herself and picks, you from emotions and fatigue you faint...After some time you wake up and the first thing you see is Mikasa with a face of relief

Mikasa: "oh my God you're alive..."

Mikasa hugs you tightly, you turn around and notice that the titan was defeated but Mikasa won't forget this easily... With the days that follow Mikasa is much more clingy and protective, she doesn't even make you train anymore scared that you'll get hurt. One day when you were tired you shouted to her that she was becoming overprotective, so she looks at you with a death stare

Mikasa: "I won't let you go Eren...i only want yo protect you and keep you close...nobody will steal you from me Eren..."