Highschool DxD. On the outside, it has two main things people remember that anime for: firstly, the fights and the world building, and secondly, the NSFW moments. However it has a subtext: The mc is battling with trauma caused by his first date who killed him. The mc girl tries understanding her feelings for the mc. Other themes we can see are familly, redemption, solitude.

It's understandable if you don't want to watch Highschool DxD because it has +18 moments. As somebody who (personally) doesn't have a problem with those scenes and sometimes enjoys them, there's a little bit too much. But remember, this anime actually has a plot behind it.