[relentlessflame]

Originally Posted by Mura

Spoiler:

I am curious on the exception that you mentioned though.

Spoiler for Game mid-route Spoilers:

Well, it's more of a story-related technicality, and was already alluded to before in this thread. It's still the case that all sex scenes occur between people who are very much in love with each other, so no "casual sex".

Spoiler for Technical Exception to the 'no-sex-before-dating' rule:

It's Mifuyu. As you know from the anime she's very much in love with Yuuki, but she's trying to be loyal to Chisato. A large part of her route amounts with her playing with fire, and then immediately regretting it/feeling terribly guilty. She and Yuuki both love each other, and she agrees to have sex with him, but she keeps trying to deny her feelings and make it a one time thing. She thinks she has no right to be happy with Yuuki because she'd be betraying Chisato.

Basically, the whole plot plays out as if it were an adulterous relationship and Yuuki were cheating on Chisato, even though Chisato's love for Yuuki is one-sided in this route. That's the central drama element for most of her path until the end (when another element takes over).