We've all had moments of total cluelessness, missing something that was right under out own noses out of sheer obliviousness, much to the amazement of those around us. For Youta Koizumi, what he's been missing is that his twin sister Hikaru is in love with him. He knows that he spends an awful lot of energy looking out for her, but in his mind, he is the only person who stands between Hikaru and bullies who are inclined to make fun of her dour appearance and quiet personality. He's a totally normal guy with a crush on his classmate Oda. So when Hikaru kisses him on their birthday and reveals her true feelings, it seems safe to say that his world begins to crumble. He tells her she's confused, which causes her to run out the front door and in front of one of those ubiquitous speeding vehicles manga is so fond of. He tries to save her, but ends up in the hospital as well...in her body. Somehow getting hit by the car causes the twins to switch bodies, so that now Youta's the girl and Hikaru's the boy, even though only one person believes them. To make Youta's life even worse, Hikaru feels empowered to press her suit now that he's in her body. Since they don't seem to be switching back any time soon, Youta finds that his life has gotten a whole lot more uncomfortable than he could ever have imagined.

Ani-Imo may rightfully remind some readers of Your and My Secret by Ai Morinaga. The premise, if not the method, is very similar, right down to the girl-in-a-boy's-body becoming more aggressive while her opposite gets a bit less so. There are a couple of major differences apart from the obvious incest theme, however, with perhaps the most important being that at its heart, this story is a romance, not strictly a comedy. Mangaka Haruko Kurumatani is perhaps better known for her raunchier titles in magazines like Cheese! and Sho-Comi (none of which are available in English as of this writing), and she brings that sensibility to this series, which runs in Aria. Youta's main concern might be to avoid looking at his sister's body in the bath and while getting dressed, but Hikaru is all for using whatever she's (now) got to prove the truth and strength of her feelings to her brother, and there's a strange sense of earnestness underlying her actions. That she fights dirty, playing on Youta's protectiveness, is sort of a given, and provides some of the comedy in the volume. And Ani-Imo is fairly humorous, albeit in a quiet chuckle way. A lot of the humor comes from Youta's mental images and the shredding of his ignorance, such as why Hikaru always avoided Oda or what he thinks is going on with Hikaru (in his body) and the male doctor who treated them. Your particular sense of humor will decide how funny you find Hikaru's manipulation of Youta, as some of her tactics can come off as a little mean. It isn't to the degree that Morinaga's series can feel cruel, but there's definitely a sense that Hikaru may be abusing her use of her brother's body a bit.

Obviously the most contentious aspect of this series is going to be its incest theme. While attempts are made to make it okay – attempts that will end up alienating a different set of potential readers – it is likely to make you uncomfortable if this isn't your genre. Kurumatani never lets us forget that Hikaru and Youta are siblings, and while the rest of the story is fun and clearly written by a veteran romance author, incest is very much a part of the book as a whole, rather than something mentioned once or twice and left alone.

Kurumatani's artwork is in a slightly different style from her earlier work, with very distinctly pudgy faces on the girls and cluttered pages. There is a tendency for some of the characters to look very much alike – such as Youta and the doctor, who are nearly indistinguishable in one picture – but she does a good job with body language. Youta still moves like a boy in Hikaru's body, although she adapts to moving like a male almost instantly, which is interesting. (It perhaps relates to her telling him just how much she watches him.) When Hikaru bends over a sleeping Youta after the body swap, every line of his body shows yearning, while Youta backing away from Hikaru post-swap calls to mind the image of a cat with his fur puffed up. Despite the clutter, the pages are easy to read, and Yen Press' language reads naturally.

If you can suspend your sensibilities, there's a good story in Ani-Imo. At this point it is hard to decide whether to root for the main couple to get together or to get back in their own bodies – as well as the question of whether or not that would end the situation – but it's pretty fun to read while you decide.