Highschool DxD was very enjoyable and I had a fun time watching it. This anime series is very ecchi based and has a lot of good humor.
This series has a variety of different characters and all of the characters are different and entertaining in their own ways.
Definitely a harem anime. it's pretty much explained in the first episode that it is going to be a harem anime and that if you enjoy them you'll enjoy this anime.
There was nothing offensive to me in this anime and there was little to be offended about.