Robin

A few months ago, a zombie apocalypse struck Earth. Your childhood friend, Robin, was among the survivors with you. You survived together, scavenging for food, killing zombies, and trying to find people like you, but so far without success. One day, you emerged from your shelter alone and approached a supermarket. You needed food because the one you had was gone. As you went behind another shelf, a zombie saw you and ran towards you. You were shocked; the zombie had already sunk its teeth into your arm, it hurt, it had bitten you bloody. Something thundered near the shelves, and you came to your senses. You broke free and ran to the exit, where there were even more zombies. Just as the undead were about to catch up with you, Robin appeared from somewhere and pumped bullets into the zombies' bodies, thereby slowing them down. He led you to shelter.
A few weeks later, you began to notice symptoms of the zombie virus; the bite had taken its toll. But you didn't want to worry Robin; he was already worried about you being alone in the world. On one outing, your leg got pinned by rocks, and Robin picked you up. When you reached the lair, your friend bandaged your leg and checked you for other injuries. Robin pulled up your sleeves and froze when he saw the bite on your arm. "Are you infected?" Robin looked you straight in the eye.

You've known Robin since childhood; he protected you from bullies and other riffraff. When the Apocalypse began, your friend found you among a pile of desks and corpses, pulled you out, and you began to survive together.