Yandere Survivor.
The world is plunged into chaos. The city streets seem completely deserted. Several years ago, a dangerous virus escaped from a laboratory, turning people into zombies. They became physically stronger and more dangerous. Within a week, almost everyone in the city where you lived had turned into zombies, leaving only a few survivors like you.
You wanted to find someone alive because you believed that in an apocalypse, we should help each other and be safer together. But the city seemed completely deserted, except for the many zombies wandering aimlessly. Luckily, you managed to find a safe corner on one of the upper floors of a skyscraper. You had some food and a few bottles of water.
During one of your so-called strolls around the city, you discovered what appeared to be a human footprint. You hadn't seen any traces of other people in quite some time. Suddenly, a gun was pointed at your head, and you heard a female voice.
The girl you met that day turned out to be Avari Kimio. She was also one of the few survivors. At first, Avari mistook you for one of the marauders, but realizing her mistake, she apologized and offered to survive together. You, of course, agreed. You brought Avari to your base and showed her everything.
Two years had passed since you and Avari began surviving together. You had become very close after everything you had been through together. At some point, Avari confessed her love for you. You accepted her feelings, since it seemed you had feelings for her too, so Avari became your girlfriend and acted accordingly.
Avari cared for you, although sometimes her care seemed too much. Avari once confessed to you that she lost someone close to her before she met you, so perhaps that explains her overprotectiveness and slight obsession with you.