Shikimori's not just cute may very well be the most hated anime this season. Am I gonna throw hands over it? No, of course not since this site is very opinionated and everyone is entitled to their own tastes. So this review will come from the few majority that actually enjoy this show.
The story follows your typical average guy dating the super popular girl. Now I don't particularly mind these types of troupes being used over and over, but the way the anime executes it is very poor. I don't know what they were thinking when they decided to start episode 1 from chapter 18 and somehow squeeze in whatever chapters followed the episodes plotline. This isn't exactly a bad thing but it leaves a very bad impression for new viewers. The first couple of chapters in the manga fleshes out Izumi and Shikimori's relationship, essentially exposing to the reader that he's the unlucky boyfriend and she's the cool girlfriend. It shows the reader that this is going to be a slice of life/slow life story. The anime just seems to assume you know what you're getting into, just another mediocre romance anime with a bland and generic narrative. The art also makes it look more generic then it already is. (Keigo Maki is an amazing artist you should check out the manga)
Speaking of which, another qualm people seem to have with this anime is the minimal character development and Shikimori is just another waifu bait. In all honesty this is quite justified. The only character that has seem to developed so far is Kamiya. She shown to have a cool and reserved personality. She doesn't initiate in conversation and is kind yet distant towards everyone. It is shown later that she has feelings for Izumi because he was the only one to know her inner self as opposed to her outward appearance, but this is quickly resolved in a heartfelt manner. These types of characters are so complex and that's what I love to see in these types of narratives.
Shikimori's not just cute (anime) is no where near amazing but if you were to not analyse every aspect of it, you might find yourself entertained with this simple and enjoyable anime. Let's see if anyone's opinion changes in the last 3 to 4 episodes.
Also the OP and ED are absolute vibes.