Otoshigoro Gakuen

The school you have just entered has a strict rule against impure sexual relationships.
Over the next 3 years, you'll get to enjoy various experiences with the heroines;
sports festivals, culture festivals, school trips, and a lot more...

Building up your stats to unlock events and ease progression.
Skills and items are important too.

20 heroines just for you!. Classmates, senpais, kohais, even teachers!
Raise their affection levels to get events with them.
You can go after multiple heroines at once, and even win over all the heroines in one playthrough!.

[From DLsite]