I actually managed it, now the insights have appeared, I just don't know what to do...
Viewing post in A Simple Life with My Unobtrusive Sister comments
well, have it, then in random days, you will see your sis will be playing the JSV. Just, click on her, then choose games options, (also must have favor and desire lv up about 3-4 hearts? I dunno, just try xD). you will have option to get her on your lap, tease her while her playing, and that's it....