I'm not sure about that; most shoujo go through the relationship development phase quite quickly, to cement the characters as a couple and then enjoy various shoujo moe things like dates, rivals, and so on. Which, in turn, is also standard formula for this medium. Whereas shonen and seinen are entirely built on the "will they be together or not?"Shoujo at least has variations in relationship progress depiction unlike something like shounen romance manga, where authors just repeat the same formula.