Okay I was an idiot..You probably meant you didn't know how to use the walkthrough XD. Well, let's say you want to go for Caramia.(the first guy in the guide) Under Fuka's picture, you'll find こんにちは in bold and that's what you're going to start with. That guide makes you save many times since some guys can have a few choices in common..I think it's too troublesome so I don't so that a lot myself .:D Anyway, when you see something like
this ,it means you should save
before you make that choice, so that you can load it later to choose something else in order to get a different ending.
Anyway, starting form the second choice in the game, you can just choose the ones in bold under Caramia's picture..
Something like
this means that you should load from save no.16 (assuming you saved the game at that time,before making that choice, according to the guide) and choose the opposite choices in order to get another ending for Caramia.
Each guy(or maybe only some of them, I haven't even played the game XD) has more than one ending, and in order to get Fuka's 'true' ending and know the full story behind everything, you need to get
all the other endings...All the good and the bad...
I hope that helped a little...If my explanation is unclear please tell me :D.