'Half and Half' is a manga that doesn't know what it wants to be most of the time and derails itself spectacularly in the last 2 chapters. Most of it is a surface-level exploration of a cis woman (Hina) being attracted to the past male self of a transwoman (Itsuki), with Hina not knowing what to do about her feelings and how to approach the new Itsuki. The manga baits you into thinking it'll be a love story between the two, but it isn't; that it'll be about Itsuki's struggles as a transwoman in the conservative late 2000s Japanese society, but that's only a few lines here and there; that it'll be an in-depth look into gender identity and attraction, when it's... well, just read below.
Considering its topic, the manga contains a lot of transphobic sentiments towards Itsuki—which I take no issue with when it's coming from other characters, as it is expected; what I do take issue with is the way her character is handled. For a story centered on a transwoman, her perspective is constantly overridden by other people's who only refer to her as a "gay guy". If the mangaka was trying to point out that trans people deserve respect, having the rest of her characters refer to Itsuki as the wrong gender without any correction kind of nullifies her entire point, no matter the intent.
The ending is rancid, and the mangaka shot herself in the foot with it. So, let me get this straight: you write a story; 90% of it, a transwoman is explicitly attracted to men, and is happy to present as feminine. Then, you end that story with her deciding to date her cishet female friend and stop presenting as a woman. Somehow, against everything you established, this is a happy outcome. What am I missing here. Even if Itsuki can reconsider how she identifies and whom she dates...there's not enough of her perspective to indicate how such a radical change takes place. She barely has a voice when it counts, and ends up being more of a circus attraction than a character.
It's like the take-away from this manga is "OK sweetie, you've had your fun but summer's over and it's time to go back to normal". Then there's Hina accusing Itsuki of "playing with her feelings", when Itsuki tells her repeatedly that she can't give her what she wants and isn't attracted to women. There's this gross implication of Itsuki "tricking" Hina, when in reality Hina's too selfish to take "no" for an answer, refusing to accept that the person she was so hung up on 13 YEARS AGO (goddamn!) is no more.
The manga does have moments where characters broaden their perspectives and learn to accept modifications to their strict worldviews — sometimes it happens suspiciously fast and easily, even. The art is also great and appealing, and as piss-poor as the ending was, there were a few good moments such as the chapter featuring Marui, and Hina staying her tomboyish self despite being repeatedly told that she's "ugly" for not being typically girly-girl feminine. Too bad she couldn't extend the same consideration for Itsuki and let HER be her true self as well.