First of all, thanks for the comment and sorry for the late reply...
In this early stage, the game is still on the rails as we have yet just a very little content... we are releasing more content with each new update.
**Spoiler**
Yes... inevitably you will have to seduce some girls while you search for the dream girl... not necessarily all of the girls in the game, because every time you finish the story with one of the girls, you will get a clue to find the dream girl.
When the clues are complete, you'll choose whether to stay with the girl in your dream or one of the girls you've seduced and dated.
But the idea is that we'll have much more girls than we need to get all the clues (we are expecting dozens of girls in the final version but you need to get 8 to 10 clues to find the dream girl), so at a certain point, you'll be able to choose which girls to invest in and which not to invest in, to get the clues. You won't need to seduce every girl in the game (unless you want to, of course).
But yeah... every girl's story is on rails.