I saved a s*x slave and she will be my new friend. (Re-written.)

After defeating the Demon King, all I want is to live a peaceful life. A normal life... Although it's harder than I thought. My dream is to have a girlfriend and friends. If I can fulfill one of those dreams, I'll die happy. One day, I killed a group of bandits and rescued a sex slave. I turned her into a vampire and gave her a new life. "You'll be happy again, I promise you!"