It's a romantic comedy about two online gamers who don't know each other in real life (yet). They're both aged 30 or so. Sakurai is surely a virgin and has no social life beyond occasionally chatting to a loud, pushy male colleague called Koiwai, but at least he's got a job and can pass for real-world functional. Moriko, though, is a NEET. She quit her job because it was making her miserable. Now she slobs around the house all day, living off her savings and forgetting to eat. She wears any old clothes, she's a human wreck and online games are her emotional lifeline.
The online fan community loved this show. Moriko and Sakurai aren't just adorably dorky, but also so true to life (for that kind of person) that lots of viewers identified with them directly and personally. Even if you're not an online gamer, though, it's still enormously relatable. Moriko adores her online life and her online friends, but drag her away from her computer and she'll have so little self-esteem that she'll be thrown into panic and confusion just by having someone talk to her. Also, wonderfully, her voice actress sometimes makes her sound like a gremlin. There are so many accurate little details here. The "cool but I'm a geek for thinking so" of Sakurai's matching pink keyboard, hoodie and phone case. The subtleties of the four-way relationship that these two people create for themselves, since both are pretending to be the opposite gender online. (Their online personas are called Hayashi and Lily and you'd describe them as "different but related", to the extent of having different voice actors.)
However I said "loved". Someone read the director's Twitter feed and discovered that he's a neo-Nazi who rants about Jews and says things about Hitler's gas chambers.
I won't defend this man. Obviously he's another anime otaku who desperately needs to get outside more, but that's no excuse. I'd be happy if he left the industry and I feel bad for the original manga's creator. However I knew all that going in and it won't stop me talking about this show.
It's built on daft coincidences. Online acquaintances happen to live near each other, and much more. To enjoy this show, you've got to accept mind-boggling levels of absurdity. (This is actually easy, though, since it's a charmingly dorky romantic comedy rather than, say, a gritty thriller.) However it's worth pointing out that the improbability is less extreme than it looks to us, since the Japanese-speaking online world is much smaller than the English-speaking one.
It's a happy story. It'll take Moriko and Sakurai forever to get over the tiniest hurdle, because they're... well, themselves. They're hopeless at date stuff. You'll be cheering them all the way, though, and celebrating when, for instance, someone eventually manages to say something. Moriko's faces and reactions are adorable. The show's gentle and lovable.