Yes, the feel of the story really does resemble a plot of a shoujo manga, the authors attested to that as well. The moe for me came from the main character, and pretty much everybody else helping out Sumomo to become a stronger person. In the beginning of the game, she looks like one of the most fragile things ever to have existed, so maybe her mental development over the whole
may be more important for the moe factor than first impressions. But then again, I haven't seen the anime... yet.
BTW, great news about the seiyuu cast. I'm glad.