i began playing the game today and played it through in one session (i already know the game, so it's easy for me to get through).
knowing ya older games i also know that, when saving at a part where you have to choose endings, paths, whatever the game will never show ya the text of what you can actually do when you reload there, so ya gotta remember it (and that might actually be the cause of that bug?) or look around or do whatever to get the infos you need. anyway, since i just saw that text seconds ago before deciding to reload i knew that i just had to press a number to get to my ending. but when i pressed 4 i suddenly didn't get the ending. instead the game was tellling me that i did somethong wrong to that girl and therefore couldn't get her ending (the heck? all the girls had 100 trust and way more than 100 lust, including rio). then the game showed me what else i could choose from instead and suddenly, instead of having 12 different endings to choose from i only had 1-7 (4 was missing too). oh and i couldn't undo anything anymore, since i loaded a save file.
so i guess it's the specific cutscene where i decided to save my game that created a weird bug.
pity, i wanted to see those bonus endings 11 and 12 :/.