By Yuyuko Takemiya and Zekkyo. Released in Japan by ASCII Media Works, serialization ongoing in the magazine Dengeki Daioh. Released in North America by Seven Seas.
There is a certain subgenre in the anime/manga/light novel world that involves short, young, angry girls meeting rather nebbish reader stand-in guys and arguing/whining at them until they fall in love. When made into an anime, the girls tend to be voiced by Rie Kugimiya. Of these, Toradora! is possibly the simplest and purest of the ones we've seen over here, if only as there is no magical powers, or supernatural content, or ridiculous situations (see: Zero no Tsukaima, Shakugan no Shana, and Hayate the Combat Butler). We just have the simple story of an incredibly pissed-off girl and the guy she slowly falls for.
Our hero here is slightly less nebbish than most love comedy heroes. He's Takasu Ryuuji, a nice young man who is unfortunate enough to have 'thug eyes' - in other words, he always looks like he's angry and glaring at you, thanks to the genes of his dead yakuza father. He lives in a small house with his hostess-club mother (more on her later), and is looking forward to a new school year with a new class... well, not looking forward to a new group of students misunderstanding him, but... see, there's this girl in class he has a crush on. She's cute, she's happy, she's kind of a ditz. He doesn't have the guts to converse with her, but at least they're near each other.
This is when he runs into our heroine - literally. Aisaka Taiga is very pretty, with long, flowing hair and a cute face... which is usually twisted into a snarl, as she's inevitably angry at the world. She's also 4'8" or so, and therefore makes an amusing contrast with the average-sized Ryuugi. She immediately takes a dislike to him, and I was expecting the plot to be their slowly getting to know each other over the course of the series while interacting at school. Little did I know... one afternoon, Ryuuji goes to retrieve his schoolbag, and meets Taiga, who's suddenly panicked, and tries to take the bag from him. We find out why when he gets home - she had put a love letter in the bag... for his best friend. What's worse, the letter is only an envelope, she had forgotten to put the letter in it. And then she shows up in his room at midnight to get the letter back.
Yes, it turns out that our angry girl is secretly (or rather, not-so-secretly, as we see as the volume continues) a "complete spaz", as Seven Seas translates it. What's more, like all anime angry girls, she has a soft, sweet side, that so far only her friend Minori has ever seen. But Ryuuji gets to see a bit of it here too. What follows is, to be honest, a bit 'tsundere-by-numbers' as Taiga and Ryuuji team up to help each other win their true love (her best friend is, naturally, HIS crush). Each successive attempt is a giant disaster, and it's noticeable to everyone in the whole world (except the two of them) that they're made for each other. Indeed, since she lives in an expensive apartment next door to his house, and he goes over to make her breakfast/get her up (as she's sort of useless that way), the rumor is they're lovers...
There's next to nothing here that's original. Taiga is another young-looking tsundere girl, Ryuuji, despite his eyes, is the typical harem manga lead, with a vague sarcastic streak to him that you see in such leads nowadays. Taiga's friend Minori, meanwhile, makes me wonder if the writer had been reading Bleach before she came up with this, as she's eerily familiar to Orihime Inoue, the head in the clouds girl from that series. The one exception I can think of is Ryuuji's mother who is... well, a blonde, big-breasted hostess girl who looks about 16 years old but is clearly about 33 or so, works all night and sleeps all day, and is dependent on her son to do everything for her. I've seen this type occasionally in anime and manga, but rarely in so... pure a form. I kept waiting for her to give out pointed advice or something against her type, but no, there's even a final side-story that shows us that she is exactly what she seems. Ye cats.
Despite the lack of originality, there's nothing here that's actively annoying, provided you don't mind the tsundere archetype that Taiga/Shana/Louise/Nagi provide. If you do, you likely already planned to avoid this series anyway. Otherwise, it's pretty much a manga that knows its audience, and delivers what its audience wants. Be warned, though, there may be shenanigans, and perhaps a zany scheme or two.