Quick update: Found out how to buy Ice cream, I don't get what to do with it though. Also figured out you have to go the bar and talk to a guy near the middle (you will know him by a little bit of red text appearing when you talk to him) and then head to "Sexy Girls!" place and there should be a pink haired woman off to the right side of the stage, interact with her and pick the first choice, then go back to the same man and he will teach you something, then in the afternoon, approach the little sister where you last found her and she will fuck you. Once again a mandatory H-scene. Hold up! FUTA-TIME BABY! When you're done with that, change it to afternoon and then go the school, second floor, talk to the elder sister and she'll start to fight you, go to items and there should be two items you haven't seen before, one of these items will give you a victory over her. When you have finished up with her go to the oni house at night and an event should play out, go back to the second floor of the school and the elder sister will dump her boyfriend and fuck your brains out. Talk to the little sister where the old lady is again and she'll run off. She will be in the slums/casino area, in the bar, go there at night time and then talk to the bottom right most man who has slightly grey skin and select the first option twice and then the little sister will get fucked by him. Then there should be littele else to do from what I can find, as far as I know you can now attempt to fight the mother, to do this, you need to go to the oni house and interact with her book, you need to select the second option twice if I remember right and then a scene will play out and you will be in your combat gear and heading for the final battle.