Sora no Iro, Mizu no Iro, Overflow Recommendations
While their settings are completely different. Both of the sex scenes from their first episode's sequence are remarkably similar in a good way. While Sora no Iro, Mizu no Iro leads a secret sex life on campus direction, Overflow follows the path of incest.
If you loved the high quality animation and artwork of Overflow's first episode, you will find that Sora no Iro, Mizu no Iro is a masterpiece in that regard.