Imperfect Girl arrives on the scene with a significant pedigree: it's a manga adaptation by Mitsuru Hattori (the creator of Sankarea: Undying Loving) of an original 2011 novel by the prolific NisiOisin. Unfortunately, the end result is not special in a positive way.

The intent of this work is to be a moody, stylish character study about a young man who overthinks his way into a mess of trouble thanks to an odd young girl. Laced throughout are various mystery aspects, such as why the girl seems to be alone and what the deal is with the strange, shadowy fish-like shapes that seem to hang around her. (Are they even real? The way the story is going right now, they could just be figments of imagination.) The production aims for style points by never naming the protagonist and giving only a nom de guerre for the girl, under the auspices of this being an event account, so the girl's real name shouldn't be used.

Unfortunately, the tale itself lacks the realism necessary to pull off this illusion. The girl's behavior is so bizarrely unfathomable that not even a reasonable guess about her circumstances can be made at this point, and she shows a degree of independence that does not jive at all with her being a 4th grader. So far she functions more like a plot device than an actual character; she can do whatever is needed for the story to move forward, whether that's lying in wait for the protagonist in his apartment or moving with unnatural swiftness.

The other big problem is the protagonist, a self-proclaimed writer who can produce rapidly but has concluded that his writing lacks the spark it needs to make a breakthrough into publication. While being taken to the girl's house at knifepoint, he has multiple opportunities to escape but talks himself out of them; in fact, he talks himself into a bad situation by being unwilling to oppose the girl even in easy circumstances. The intent is to portray him as going along with this so he can find that spark he needs without openly admitting that he's doing so, and a couple of comments indicate that this incident took place 10 years in the past before he became a novelist, so it must have worked for him that way. In execution, the protagonist comes across as either masochistic or flagrantly stupid, perhaps even both.

Although Hattori's artistic style can be discerned in some of the artwork's broad strokes, the design effort in both characters and backgrounds is substantially different enough that it may not be immediately evident that this is the same artist behind Sankarea. This is definitely a more darkly-shaded work, filled with levels of solid black that try to lend weight to the more mysterious aspects of the story; even text boxes are often black with white print. The slight goofy undertones of Hattori's designs are also gone, instead replaced by vastly more serious looks from the mopey protagonist or the heavy-lidded girl. Character poses for the girl seem to be aiming for an effect that implies an older person in a child's body, an effect that's disconcerting but maybe not in the way that was intended.

Vertical Comics' release of the first volume offers 190 pages of story and a brief preview of the next volume – the rest is unusually sparse with not even a Table of Contents page. The coloring used on the front cover art creates some nice contrasts and, along with the back cover art, offers the prettiest artwork in the release.

This adaptation will apparently consist of three volumes, but little in the first volume encourages a continuation into the second. Neither of the characters is intriguing enough or likable enough to warrant further attention, and any pull the mystery of the girl's circumstances may have is overwhelmed by the stupidity of the protagonist's actions necessary to drive the plot.