By Yuuki Fujinari, based on a game by GungHo Online Entertainment. Released in Japan as "Otometeki Koi Kakumei Love Revo!!" by Enterbrain, serialized in the magazine Comic B's-Log. Released in North America by Yen Press.
Believe it or not, despite the obvious 'based on a work by (company name)' credit on the front cover, I didn't actually realize that this manga was based on a date sim game. Of course, now I feel stupid, because not only is it insanely obvious, but it also explains the manga's lack of backstory and lack of plot. It's fleshing out the bits in between the game sections, and therefore can't advance much of a plot. It is, in other words, pure service.
The premise of the game (which is merely implied in the manga, irritatingly so) is that the heroine, Hitomi, used to be young and cute but then discovered the wonders of sweets and is now very overweight. Luckily, she is at a school with a ton of incredibly hot guys, who are there to help her lose weight and exercise. Perhaps she can even fall in love with one of them!
I will admit, you really do get a sense of Hitomi's weight problem here. Most anime and manga, when they have characters who are pudgy or fat, tend to fudge this a little, having people say so but merely being less stick-thin than everyone else, or having them be tubby yet cute. (Satsuki Yotsuba from Negima is an excellent example.) Hitomi does not suffer from that. She's not only huge, she also has a sort of pug nose that makes her whole face seem squinty and pinched (we never see her eyes as more than dots). Interestingly, we don't actually see her eating a lot - the few points where she mentions diet and exercise, she is able to keep her willpower and avoid sweets. Presumably that's because the manga is following the 'good ending' path.
I'm not certain which guy she'll end up with here, or even if the manga will bother to pick a guy. It could simply be left open-ended, so as not to upset girls who picked another guy to end up with in the game. It's also somewhat irrelevant, as these guys are really, really dull. The fact that this is a heroine among a bunch of guys does not change the fact that this is a datesim, much like Kanon or Clannad (though with far less soul crushing angst). So you have a wide variety of guys to choose from, depending on your fantasy. The stoic respectable leader, the cute shouta, the yakuza hair, the sassy teacher, the vaguely ill bookworm... all these characters are here for your love love needs.
None of them are fleshed out, though. I've no idea if they get more characterization in the game or not, but it is quite frustrating as a manga on its own. This title simply doesn't work without its parent to refer to. As a complement to a game, I imagine it does its job adequately, giving us more scenes of the guys in action at school (Hitomi doesn't even appear beyond a cameo in the first chapter). And the guys seem handsome enough - despite the lack of BL in this series, I can see why it ended up in Enterbrain's BL-friendly Comic B's-Log. As a manga, though, I can't recommend it, unless you've already played this in Japanese. There's just not enough going on, and the guys are cyphers.