Japanese law requires all pornographic media such as erotic visual novels and live action porn to be censored. Even a lot of the lewd art that people make on their own and post to sites like Pixiv are censored.

However, nudity patches do exist for certain games. Other times a skilled Photoshopper will change the image so that it is no longer censored.

Explicit images are not displayed on Konachan.net at all, so that might have something to do with it? Otherwise, if you have no tags in your blacklist everything should show up normally.