I would like to start things off by saying that people who completely detest ecchi stuff might find this a bit unappealing. There is not a ridiculous amount of it, but I am just giving you a heads up. I myself am not too fond of nudity in anime.
With that said this is one of the few anime that make it work. I put it in the same category as Food wars and Prison school.
The first OVA made me cry a little too much from laughter, but....I recommend that for male viewers.
The humour, the facial expressions and the voice acting (when listening to the japanese version with english subtitles) is glorious. Unique characters, no horrible cliffhangers and the list goes on. A lot of plus points there.
Even if you are not into it by the first season, the second season will make it hard for you to breathe from laughter. Trust me, for most people this whole anime is worth it.
There are not many good comedy anime out there nowadays. You can probably count the good ones with both your hands. So please, check it out the gem.
I will also note that this is NOT a harem. People who declare that it is need to read the definition of the word. I utterly dislike harems, so rest assured. This belongs in the categories comedy, action and adventure.
The rating 9/10 is because season one had a few flaws that made it imperfect. Don't let that stop you!