For starters the word you were after was EFFECT not AFFECT...On to the real issue tho. His point was that if you are a collector then you want that 100% Affection level for the hentai scene in your book. You need 100% to unlock that and you need max lvl and evolution to unlock animations.
Also for anyone who decided they want to try this game on HARD MODE setting you can go through it with 2* and 3* girls only, you will only get so far before having to get rid of the 2*s for more 3*s or 4*s but it is quite a long way before you need to do that.