The following titles are not reverse harem, I repeat not a reverse harem. But I swear that they're all related to reverse harem.
Hakuouki Reimeiroku- 12 episodes
It's the prequel of Hakuouki series which illuminates the rise of the shinsengumis. The missing presence of Chizuru almost turned me into a fujoshi. She makes a cameo though at the end. As much as I love Hakuouki, it was really hard for me to pick it up again after only watching just one episode a few years back. But I found out it was way harder to finish it. The only thing that I appreciated is that we get to see a different side of our pretty warriors most especially Souji.
The Selection series- The Selection, The Elite and The One by Kiera Cass
The trilogy is about America who enters the Selection to compete for the prince's hand in marriage. Think Hunger Games meets The Bachelor. But it's more of a political arena and not your typical romantic dating game. You may be wondering how this young adult bestseller got into reverse harem. The reason is exciting and is actually simple if I have just used my reverse harem common sense. There's a new installment coming out this May 5 with the title, "The Heir". For the first time, the Selection will now be held by a princess and with 35 boys vying for her attention. I personally find the series lacking and I find myself falling for the jilted guy again but this turn of events had really gotten me excited and I just had to read it right away! I've added the The Selection series and The Heir on the store tab. The first two chapters of The Heir are also out. Go search for it! Thanks Anon for the tip!
Please Save My Earth OVA - 6 episodes
It's a story about a group of young boys and girls having dreams of their past selves. Their past identities are a group of alien scientists stuck on the moon. The OVA covers the first half of the manga and has not shown any reverse harem potential. But in the manga, all the male scientists will all fall in love with the heroine on the moon. The animation is old but I love the premise and the OVA left me wanting for more. I've watched it way back but I still have not had the time to read the manga. I'll post a proper review once I have read the manga. Thanks to Jaina for the tip!