Character image set for: [Nyan Nyan] Osakoi ~ Ore to Futari no Amaama Gohoushi H Seikatsu ~ [娘娘(ニャンニャン)] おさこい ~俺と二人の甘々ご奉仕H生活~ https://e-hentai.org/g/930390/f54aeec7a9/
Question, were the images originally BMP format? Because if so, it's highly recommended you clean the backgrounds with Photoshop or XnView before uploading.