You'll want to reread through the guide, and make sure you know what kind of yandere you want. For the basic or anykind of yandere. I recommend finding a girl that's a bit crazy, first, be her friend, and be a good friend. Slowly as time goes, get closer into her heart, and make her want to hang out with you.
It seemed to be the perfect solution but what would Colin say if she suggested it. Mary wondered what Samantha would wear for the meal at her house. Would she still be the maid. Perhaps she would dress less formally.