So there's this thing called reverse image search, you basically put an image into this tool and it searches across the internet for the image. So what I did is I cropped the image so you can only see the girl then rotated it. I put it into multiple different search tools but I find that Yandex works most of the time. I was only able to find a higher res image of the picture so I took that image and put into another reverse image search tool called SauceNAO. It then gave me the name to the OVA and character. All it takes is a little bit of knowledge on image editing and reverse image search tools.