I've no idea how or why this series manages to keep going, although it's based on a visual novel that might, perhaps, theoretically, have fans. (If so, I'm appalled and I don't want to meet them.) It's had three 4-episode seasons, with episodes released in 2017 and 2019-21.
Our fat, sinister anti-hero in a face mask is upset that his relatives are about to inherit a house. One of them (Reina) is getting married next week, so what if he ruined her life and drove her out before then? "Welcome to the horror mansion where I stand guard!" He uses his secret cameras to film Reina on the toilet and during masturbation, then threatens to release the footage on the internet if she doesn't have sex with him. I'm pretty sure normal people would take one look at him and refuse anyway, but this is hentai and so Reina isn't one of them.