Invaders of the Rokujyouma!?

Both series feature a bunch of supernatural girls who shouldn't exist in the same universes together. Seems legit.

I really liked Kore Wa Zombie desu ka? Also have really like what I've seen from the first few episodes of Rokujyoma no Shinryakusha. As far as similarites, both very funny, both feature a bunch of different types of girls with different powers living under one roof with one lucky/unlucky guy.

Rokujouma and Kore wa zombie, Are very a like but ina weird way different.

They are both comedy slice of lifes with a little something different, but the two can be seperated easily. 

Rokujouma is a Harem that involves a lighter type of strange people, where kore wa zombie is much darker (Avoiding spoilers at max here, be best to watch them to find out what i mean)

I cant gaurantee you will enjoy both series, as those who like Kore wa zombie may not be entirely favoured into watching Rokujouma, but if you are looking for something similar and want a change of pace from either series, i can happily ay these two will make a nice watch.

Both of those anime are based on comedy harem light novels. What they have in common (and probably less in common with generic harem LNs) is that the characters are super friendly with each other and that the series is actually quite hilarious. To tell the truth the adaptation of Kanojo ga Flag wo Oraretara wasn't all that well made and the things mentioned above were less present there. Nonetheless, if you liked one of those anime, there is a big chance you'll like the other one too.

Rokujouma and Kanojo are pretty similar in setting, but the two have a slight different approach. Nothing happens in Kanojo for a while main it a bit of a drag, where as rokujouma puts you straight in, making sure you know the details. Both are Comedy with a Harem, but Rokujouma has an interesting taste in characters compared to Kanojo, as Kanojo takes a more generic route, but the two are very enjoyable watches. Many people dislike Kanojo due to it being very generic, not so well made and in all honesty, pretty cheese, but its still worth a watch if its the genre you are into, and same goes with Rokujouma - just less cheese!

Both series are romcoms featuring a harem cast of characters who end up liking/loving the MC. If you like one then chances are, you'll like the other one.

I really liked Shinryaku! Ika Musume as it's really funny and Shinryaku! Ika Musume is also about invasion and is supernatural