Yeah it's really a bit weird... And you can also see that at the beginning of the game in the locker room, for both girls, another LI is peeking... In Red version Ruby... In Blue version Madison... And this also determines, for girls , which other girl is compatible with the relationship or not... Personally, I choose Sofia's (Blue) route and wait to see when she confronts her sister... She has a lot of information about her that could be useful in the future... Red is too arrogant and that kind of "criminal" girl is not my type...
My main girl is Grace, and of course Gabriella...