Well, I'm not really used to the shojo genre, there's something about the magical girls/silly romance that really gets on my nerves. But Hot Gimmick is an exception - no magical girls and (only slightly unrealistic) down-to-earth relationships.
The plot follows a teenager whose little sister is, shall we say, "popular" with the boys. Now big sis has to go and get her a pregnancy test but obviously can't be seen. However, even with a disguise she gets caught by resident asshole whose nasty mother owns the housing complex where they all live. Now, if the owner of the complex discovers Hatsumi(the main character a.k.a Big Sis) bought a pregnancy test she'd kick Hatsumi's family out without a second thought. So, in exchange for keeping quiet the owner's son gets to have Hatsumi as a "slave." Yes. That kind of slave. Now, Hatsumi doesn't really have a choice. The worst part is her old childhood friend/crush is moving back to the housing complex so Hatsumi's basically having a hard time.
It may seem a bit convoluted, but reading it is easy and the story flows well. It remains interesting with numerous twists. Art-wise its beautiful, well defined and clear. Many of the panels with images of the city have an almost photographic feel, which adds a nice, unique flavour. The artwork improves from volume to volume as you might expect, and the characters in particular become more defined and recognisable. Early on Shinogu and Asuza looked a little too similar, but once the artist settles in it becomes clear who's who.
The strongest aspect of Hot Gimmick is The interesting and engrossing characters. Characters like Hatsumi's sister and others become much more important and more depth and empathy is brought into play. You start to make predictions about what will happen next, and when you get it wrong you're pleasantly surprised, when you get it right you feel a sense of satisfaction. As the plot evolves, so do the characters and its a true testament to the author as to how attached you become to the book and its characters.
I'll openly admit it here, this manga is the only time I've felt like crying for the characters since I read the hobbit. While reading this you get a genuine sense of emotion and empathy for the characters, you feel bad when Hatsumi gets hurt and you feel great when two get together (although in the main boyfriend-girlfriend relationship you feel more suspicion than anything). It is not hard to fall in love with this series because of this. Every volume provides something new and interesting with revelations and twists.
But where the series really hits home is the overall feel and originality - sure the artist isn't the best in the world, but the characters still seem alive and beautiful. The plot can be slightly predictable at times, but you still feel surprised when your predictions are right, and while it may be the "in" thing to lavish praise on Hot Gimmick, it's a rare and truly deserving case of the hype being right.