Sometimes, the source material really is better than the anime. In the case of Kashimashi: Girl Meets Girl, this statement rings true. As I stated in my review of the anime, this straightfoward gender-bender love-triangle offers both a touching love story, and a feasible look at gender identity (as feasible as a story involving aliens and overnight sex-change could be).
Instead of re-hashing my review of the anime, I'll point out why I think the manga does a better job. To put it simply: pacing and plausibility. Where the anime spirals toward a contrived climax that requires a choice out of the pathologically indecisive Hazumu, the manga provides a more deus ex machina scenario that jibes better with her personality. Without spoiling terribly, the manga further attenuates the tension between the protagonist and Tomari, which means the final act flows better than the on-screen version. What's more the storyline here also provides the added benefit of explaining Hazumu's sex change, albeit with a little alien-science mumbo-jumbo.
All-in-all, the manga contains less DORAMA than the anime, but actually comes across better for it. Though Hazumu steals a larger portion of the focus than she has in the alternate telling, the real tension still comes from the two girls in love with her. The more dire stakes of the comic also add a sense of urgency that the show needed to bolt on by playing up Yasuna's unique condition.
Lastly, the omake chapters go a long way toward enhancing the inherent comedy of the series and become welcome additions as the story turns more serious. Given that the auxiliary cast spends little time in the spotlight during the main story, the extra vignettes really fill out their characterizations in a delightful manner.
Yasuna, Tomari, and Hazumu look lightyears better here than they did on screen. The large-eyed expressive character recieve incredible attention to detail and rarely suffer from proportion issues. Additionally, Katsura-san's artwork features some ambitious layouts that help highlight out the story's important moments. Thanks to the combination of this quality storyboarding and some ephemeral, shoujo-tastic spreads, readers should find much in these books to drool over. The only gripe comes from the fact that Katsura's artwork flails a little during the chibi and comedy portions. Funny as they are, they lack the quality and care apparent in the more serious content. The frequency of these interludes means that at least once per volume, I wonder if she was even paying attention to what she drew.
While Hazumu doesn't perform her random change of personality toward the end of the story and Tomari doesn't seem like such a wet-noodle, the manga fails to make adequate use of Yasuna (arguably the best part of the anime) and barely touches the auxiliary cast. Larger roles for Sora Hitoshi and Tomari rob Ayuki and Asuta of some of their time in the sun and hardly any time gets spent on Yasuna's family trouble. Though much of this inadequacy comes from the tight pacing that the story maintains, the flattening of the beautiful flautist removes some of the impact from the work.
All that said, this verion stands head-and-shoulders above the anime. The superior art and more coherent stoy propel this manga into "read" territory for yuri fans by a mile. The Seven Seas' Omnibus edition (which I read) collects the whole thing in two extremely afforable volumes and make it into a no-brainer. Simple, easy on the eyes, and satisfying: you can't ask for much more from a manga.