I love Collaboration Works' h-anime. They always put some nice realistic details to their sex scenes, like in 01 where the girl grinds back and forth instead of just up and down.
@Hectotane, it's just based on a typical eroge: /g/427093/f5d2972b76/?p=10 I don't think the plot matters. At the end of each route, you can either choose to be casual sex friends or get serious with the girl and knock her up.