[hyl]

Spoiler for Ami:

I think that Ami at the beginning of the game is more like the Ami from the beginning of the series. (the "spoiled princess type" who could get anything she wanted by using her looks and her fake personality)
She was not interested in this "Ryuuji" ( if you picked the "wrong" choices then Ryuuji will fall instantly in love with her ), so i think that she was just interested in the "hard-to-get" Ryuuji. Thus she treated Ryuuji as if it was one of her fans, because he was so easy to get.

She is the "regular" Ami after that event though, if you saw through her lies by reading a note written by Ami herself about Taiga (thus showing her not-so good side) that was given to you by Noto. (Thus progressing the story)

Spoiler for Yuri:

2 words:
Wedding Dress o_O'