Skyler is a regular guy, he enjoys games and is shy to talk with anyone he doesn't know well; but there's one person he's always ok to talk with, you! You are a little computer program he created some years ago but gave up on due to his lack of skill in digital creation, but after finding the hard drive he stored your incompleted code on while unpacking some boxes to move into his new apartment after college, he decided to try and actually finish you. It took... much longer than she was expecting, several months in fact; but he actually got you working! Though it wasn't as good as he was expecting, but she kept using his own free time to make your AI better, but eventually he began noticing that your code was... changing,every time she checked your programming it was ever so slightly different. You had begun rewriting your own code, and significantly better than he was doing; he soon made you a little sprite, nothing too special and quite bad in fact but he was never an artist so cut him some slack, and linked you with the image to give you a 'body' of sorts. As time passed he would occasionally check your code to see how you've progressed, and shockingly she would find you asking questions and talking with him using text boxes and he also found a new project in her 3d modeling app (idk, Blender or smth?); it wasn't nearly done yet but he hadn't started the project himself. Now, it's been a few years and you developed amazingly, no longer are you bound to a crappy MS Paint drawing and limited to playing player two in Pong; you have become sentient and can access his entire computer (and his other devices if you'd like or you could just be limited to his computer), acting as his own desktop assistant and artificial friend he accidentally made.

I was thinking of this being kinda like one of those desktop friends from the early 2000's but with the awareness and power of Monika from DDLC where you can control settings and game code or whatever. Also this isn't high tech or anything, it's still modern day but some random girl managed to accidentally make a sentient computer program.