To my surprise, I ended up disliking it quite a lot. Other people have found it charming, but I found it unpleasant.
It's about a hopeless anime nerd (Haruto) who's so deeply in love with anime, manga and games that he's renounced real women. (Frighteningly, otaku like him are probably the target audience for this show.) One day, he buys some 1/6 scale 25cm anime figurines... and one of them comes alive. She's Buzz Lightyear! Well, sort of. She's Space Explorer Nouna, the main character of Haruto's favourite anime, but she thinks her backstory's real. She thinks she's visiting a planet of giants.
After some misunderstandings, they eventually straighten things out. Nouna finds a marriage certificate (because, yes, Haruto is that pathetic) and agrees to marry him. Haruto's very happy about this.
The basic idea I quite like. I've enjoyed similar shows before. Unlikely romance and fantasy girlfriends are everyday occurrences in anime. I'd have happily watched a show about Haruto and Nouna, but unfortunately it soon starts introducing other 1/6 scale figurines to make a small plastic harem. There's Belenore (fantasy RPG character), Subaru (fighting game character and herself a hardcore otaku), Ruu (mobile phone game character), etc. At least four different unhealthy wank fantasies are being crunched together, so let's break them down.
1. HARUTO HAS BOTH A WIFE AND A HAREM
Admittedly there are other anime that do this, but I've never liked it. In harem anime where lots of girls all love the main character, obviously each girl is liable to represent a different sad male fantasy. What if one of those was "wife"? One girl could call herself the hero's wife and demand special treatment. That might not sound so bad, but it can get disturbing when the hero goes along with her assumptions. He lets her go on thinking that they're married. He doesn't contradict her, either when they're alone or in front of other people, but he doesn't change his behaviour either and just treats her as another member of the harem.
Some such "wives" believe in open marriage, of course, in which case there's no problem. (Yes, there are such anime.) Others don't, making the show uncomfortable. Nouna doesn't. You wouldn't say that she's uptight about the situation, but she's not happy about it either.
2. HARUTO IS AN OTAKU WHO LOVES HIS GAMES, ANIME AND MERCHANDISE. WHAT'S WRONG WITH THAT?
This is unarguable, although it overlooks the fact that the girls are sentient. From this point of view, Haruto is merely staying in-character when he buys figurines, watches anime and spends all his time (and real money) on a mobile phone game. When Nouna bans him in ep.3 from playing games and watching anime that contain female characters, this seems absurd. Reading manga is not the same as cheating on your wife.
3. HARUTO IS CHEATING ON HIS WIFE
As far as Nouna's concerned, anyway, he is. He'll get obsessed with other girls, find them sexy and spend all his time with them... and they're sentient figurines like herself. Some of them even have bigger boobs and fanservice shots (although this is kind of absurd in a show where all the plastic figurines are CGI-rendered and hence unsexy). Admittedly no one's having sex (which would be physically impossible), but it still feels like cheating to Nouna emotionally. Of course I'm applying real-world logic to an absurd situation, but Haruto never contradicts Nouna's logical premises. He doesn't disagree when she says they're married. She keeps calling herself his wife and he never raises a peep in response. He doesn't disagree when she accuses him of cheating. He could have laughed off her accusations with a bit of common sense (e.g. what does "cheating" mean in this context anyway), but instead he'll just look guilty and try to avoid answering.
4. IT'S OKAY FOR THE MAN TO CHEAT, BUT NOT THE WOMAN
Haruto's cheating on Nouna with all these girls. That's not true in any literal sense, but that's how it's being framed. It's the show's format and we're being encouraged to see it as charming and harmless. However there's a plot development in ep.10 that makes Nouna wonder if she's the one who's cheating on Haruto, because she's remembered a male character from her anime backstory. Their relationship was entirely platonic, but she still worries about it... but then the show twists things around so that Haruto ends up having been that backstory character! Hurrah!
In other words, a husband cheating on his wife is acceptable and funny. However a wife cheating on her husband is a plot threat that needs to be resolved to make it go away.
I found it icky. A supporting character might ask Girl #2 and Girl #3 if they felt jealous when Haruto went on a date with Nouna in ep.9... ew, ew, ew, get away from me. What the hell is that question? Everyone accepts that Nouna and Haruto are married, yet the show doesn't see that as an obstacle to harem nonsense. Even actual full-size humans are liable to suffer from harem anime characterisation, so for instance Haruto has a male best friend with a female secretary. Obviously the secretary has devoted herself to her (negative killjoy creepy otaku) boss. She shows no signs of independent thought or life and it's announced within five minutes of her appearance in the anime that she's going to marry him.
OTHER STUFF I DIDN'T LIKE
(a) In ep.1, Haruto lies to Nouna. He encourages her belief that she's a Space Explorer visiting alien planets. He means well, yes, but I didn't like it.
(b) "We'll fight to see which of us can truly win Haruto-san's love!"
(c) If you make a figurine of a magical girl, she'll be able to do real magic, e.g. teleportating humans, even if that's into specific episodes of your anime. (Admittedly this is a weak objection since reality is hardly a major concern here, but it still niggled.)
(d) A "fourth girl" arrives in ep.7. Uh, actually that's "fifth". If you don't have boobs and you're not an impossible love interest, you don't count.
(e) Ruu ties up Nouna in ep.10, binding her arms while leaving her legs free. She then discusses the weapons built into Nouna's arms and legs (which are real and got fired in ep.1) and congratulates herself on having made it impossible for Nouna to use them. Eh? Arms = yes. Legs = are you on drugs?
(f) The premise of the last episode of Nouna's anime is stupid. There are two Nounas. (Okay.) They meet on a deserted alien planet. (Okay.) They don't want to fight. (Okay.) However they do anyway, for no convincing reason, and die. (Are you idiots? Just go and have a beer.) Admittedly this gets some criticism when the other characters watch it, but I was wondering how this managed to be Haruto's favourite show.
The show does have strengths. These include:
(a) on a certain level, it's charming. The girls are nice and funny, while Haruto means well.
(b) the show has a sense of humour about otaku. It's taking the mickey out of Haruto, although not in a mean-spirited way. It's assuming that the audience are just as nerdy and isn't afraid to make jokes about it. "If things were going to turn out this way, I should have immersed myself in my otaku hobbies instead of fighting! I could have read all the hidden treasures from the back of my bookshelf. If only I'd binge-watched anime from first thing in the morning, spent the whole night playing through games over and over, and lived the wonderful life of the socially crippled!"
(c) there's a level of freaky existential horror in this premise. Most of the girls here are video game characters, so Haruto can disable their fighting abilities and change their clothes just by logging into a menu screen. (You might even find yourself in embarrassing outfits like the Pointless Bikini.) Imagine that was you. Imagine that it could happen for real. The girls live in that world. "If God exists, he must be a super sadist!"
(d) there are some fun characters. Nouna is very likeable, while Subaru the otaku is a great vehicle for nerd jokes. (She can even analyse her own fanservice scenes.)
Don't watch this show. If you feel the urge, watch an anime from 2000 called Hand Maid May instead. (Both shows are ludicrous, but they got opposite responses from me with a similar premise.) In fairness, I've seen positive reviews of this show. My reaction has been unusually negative. It thinks it's a light love comedy about an otaku and his small plastic wannabe girlfriends. Personally I'd call it a confused exploration of themes that you may or may not feel clash with each other, built around a wife being cheated on.