Have you read Hatsukoi 1/1? (same developer, actually their first VN), if not, give it an opportunity, it has a long story, likeable heroines, pure-love centered, a bit of drama and good endings (also, 3 append stories or after stories for 3 heroines)
Grisaia series is also one of best VN out there, a good worldbuilding, an amazing soundtrack, a catching story that is also very long (considering if you play the trilogy).
I also enjoyed Sanoba Witch, maybe I just like Yuzusoft art, but anyway it has good heroines, its story is not that bad and it has after stories for all heroines.