When I first saw folks compare Ze to Fruits Basket I was incredibly skeptical but after reading volumes 1 and 2, I can only describe the series as if creator Yuki Shimizu took the relationship-webbing of Love Mode and placed it in a gay version of our favorite shojo manga. And yes, I actually think this is actually a pretty awesome thing to do.
Our plucky orphan in Ze is Raizou, a half-Japanese, 18 year old blond outcast, who has recently lost his only (known) living relative, his grandmother. He's picked up by Shimizu's version of Shigure Sohma, the sake-drinking, mystery-wrapped-in-a-yukata known as Waki, to become the housekeeper for one of the Mitou family homes. From his very first moments in his new position, the innocent Raizou is shocked by the fact that everyone in the household appears to be doing perverted things to each other.
But Shimizu then pulls a really weird one on us -- unlike in Fruits Basket, the Mitou family isn't cursed, instead they themselves have the power to curse others. They make a living off this power but must suffer the consequences of their malevolent actions when they their curses rebound back on themselves and they suffer physical damage. The worse the curse, the worse the bodily consequences. However, it appears over the generations the Mitou family has dealt with that problem by having "kami," or beings that have the power to heal their masters (i.e. the ones with the supernatural powers) by making contact through the "mucus membranes." (Yes, that is the exact phrase the book uses). Waki is actually the maker of these kami, and he breathes life into paper to bring them into existence. All couples in the household are same-sex master and kami pairs, since heterosexual coupling is forbidden. (Thankfully, not all couples are male, which means for once women actually get to do something in a yaoi manga).
Raizou is pretty confused by all this (which probably mirror's the reader's confusion at this point), but honestly seems to accept this bizarre situation with an open heart. While the kami in the book all seem to have distinct personalities, there is still the troubling fact they only exist to take the suffering of their masters. Importantly, though, they have free will and do appear to choose to love their masters. In the household the only kami who seems lost and lonely is the hostile Kon, a pretty and delicate-looking young man, who becomes Raizou's roommate. Kon is a kami without a master and so prostitutes his ability to "heal" others. Clearly Kon has a healthy dose of self-hatred thanks to his own perceived uselessness, since a kami without a master seems to have no purpose in life. It is the very sweet and human Raizou, who actually has no powers and no need of a kami, that can actually alleviate poor Kon's suffering.
The first two books primarily follow how Kon and Raizou's relationship develops. Raizou's belief that one doesn't need to be "useful" in life, only to enjoy that one is alive at all, gives Kon the much needed relief from his deep-rooted fear that he is nothing if he isn't a tool for some master. Raizou and Kon may be the only pure relationship in the book that is not tied down by the weight of master-slave dynamics since they each choose to love each other and only need each other because of that love. While this is the core romantic relationship explored in the first two volumes of Ze, by the end of the first volume Shimizu is already branching out into other kami-master relationships.
Importantly, Shimizu doesn't shrink from the fact that kami-master relationships are tainted by a power imbalance -- even if love develops, it often easily became twisted and bent out of shape by the very fact kami are created for benefit of other people. I don't think this thematic preoccupation is an accident -- Shimizu's earlier series, Love Mode, about a wide variety of men who sell their affection and love to other men, also explored how power over another person's body and heart can corrupt human bonds. Ze is just getting started and there are many potential couples through which Shimizu can play out this theme in many different variations. The reason this theme never gets old for me is because Shimizu does play with the variations so much, weaving all manner of love and sexual bonds and personalities through the core concept of master-slave. The supernatural element of Ze deepens the concept quite a bit, making this tale a much more satisfying narrative read than Love Mode.
Of course, it is important to note with all this "mucus membrane" exchange stuff happening, this is a very sexually explicit yaoi that deals with sex as both pleasure and punishment. Luckily, Ze's core relationships are all consensual and it is shown that anyone who abuses a kami is going to suffer extreme consequences (Waki is one seriously scary dude when someone messes with his "creations.") It might bother certain readers that kami only think of themselves as servants who must be useful to their masters, but Shimizu doesn't let this rest as something that is an acceptable aspect of human relations.
Finally, two things to mention -- while it isn't apparent from my discussion of the first two volumes, Ze is often very funny, mixing character humor with deep pathos (does this sound like any shojo series we might know, hmmm?). While there is some heavy stuff in these volumes, there is also some lightness of spirit that makes the darkness palatable. And lastly, Shimizu has greatly improved as an artist since her Love Mode days. Although her bodies often seem to be made out of the same strange, smooth mannequin-ish mold, her character work is excellent and quite detailed. There is no lack of personality and that is what really drives yaoi, no matter what convoluted set-up is in place to explain the "everyone is gay!" environment. All in all, I highly recommend Ze to yaoi fans, and perhaps even those who were raised on Fruits Basket and are now ready to take the leap into a more "adult" (I'm using the word in the "18 and over only" sense) fantasy world.
Review copy of Ze volume 2 provided by DMP.