It's not an innovative breakthrough in drama or anything, but it's charming and funny. That's enough for me.
Sakurai is a tall, rude loner with a scary face. Uzaki is a tiny, super-busty gremlin who's chosen the... life goal? hobby? of hanging out with Sakurai and tormenting him for laughs. (It's for his own good. If Uzaki weren't around, he'd just hole up in his room and play computer games or something, or even go to the movies solo, do karaoke solo, etc.) Sakurai can't get away from her. She invites him to her house, invites herself to his flat and plays his video games when he's trying to sleep.
He's always yelling at her, but my best guess is that one day they'll randomly agree to get married. Maybe in a couple of years. (And when they say that, I bet they won't even have had sex yet.)
Uzaki's mildly sadistic and will leap on any opportunity to tease the living daylights out of Sakurai, but she's also thoroughly nice and a volcano of energy. One of the show's most important scenes (for me), is the one in ep.5 where she launches a mega-rant when Sakurai says that mint chocolate tastes like toothpaste. (Passers-by applaud.) Yes, we expect Sakurai and Uzaki to get together romantically, one day, but that's not the only thing the show's about. They're both childish goofballs, albeit each in a different way, and half the time it's as if we're watching eight-year-olds.
As for Sakurai (aka. "gloomy klutz sleepyhead villain loner")... he's rude to Uzaki when she deserves it (which is often), but he's fair. If he's wrong, he'll apologise. If Uzaki deserves thanks, he'll sincerely thank her. If you try to over-reward him, he'll refuse to accept it. He's a blunt-but-nice chap with at first no time for nonsense, although he'll build up a tolerance.
The supporting cast exists to watch Sakurai and Uzaki. I'm not even exaggerating. Uzaki's mother doesn't fit the pattern, but watching our heroes is the favourite hobby of Amai Asai, Akihiko Asai and Itsuhito Sakaki. Sometimes they gleefully meddle. I assume Amai and Itsuhito will get together one day, but right now they're basically us, the audience. They watch. They compare notes. They grumble when one or both of their targets is being even denser than usual.
Incidentally, the Asais appear to be telepathic. They can converse without using their mouths. Well, they are father and daughter.
It's worth mentioning the character designs. People who don't get out enough have complained that Uzaki's body type is unrealistic. (It's not and indeed the overblown debate became great publicity for the anime.) Look at the rest of the cast, though. You'd think the artist couldn't draw small-breasted women.
The only thing I don't like is Kuso Cat and its stupid faces. I think putting that cat in the show was a complete failure, but it's also unimportant and you can safely (try to) ignore it.
I also loved the "walk past" Mizuki Shigeru homage at the end of ep.10.
This show is basically a light romantic comedy, but one where our heroes' personalities will keep them stuck in the "squabbling best friends" stage for years. It's a lovely, relaxing show that I always enjoyed. That said, though, it's also capable of being a little bit sharper from time to time. Uzaki was a completely different person when they were still at school, rather than university. The show's also not afraid of a bit of embarrassment comedy, e.g. Uzaki unwittingly saying or doing things that make Sakurai look like a reprehensible pervert in public, or his attempts to compliment her in ep.8.
This was arguably the most prominent anime of the COVID-hit Summer 2020 season. A second season was announced almost as soon as it had finished. Quite right too. (Although this first season's better.)