[Vexx]

I think you're twisting my point a bit (or we're just shooting past each other o.O). There are quite simply choices available to characters in a college setting that are not available to a high school setting. This changes the complexity that can develop. You also can factor in the additional maturity of the characters in addressing their situations. Sure you can grind a story down to "he wants her, there are obstacles and hard choices, oh the angst" but few high school stories seem to pivot on the motivations and dreams of the girl -- a deficiency of most eroge adaptations but less a problem with manga or light novel sources as we've seen.

The college (or adult situation like Hataraki Man) - most of the players are past that "first crush/love" period that high school stories tend to focus on.