Just don't know what to next. I've done the storylines of all the character except Professor Ann. Or maybe we just need to wait for next update? 

I'm guessing the next update? I have been trying to figure it out myself,  after you do what professor Ann asks I cant find anything else to do after unless I'm stupid. the z-choice in itself is an interesting idea especially if each choice effects the story, but I just hope my choice does not include any ntr stuff because siren said the reason he added the z choice was because they thought the outcome would be controversial. I know its not a clear answer but I hope this helps in the slightest . 

I mean, most likely if it did it would be like a bad end. Usually in these kinds of games if ntr stuff is included it is as a bad end, so you don't have to see it.