i'm not particularly impressed. firstly, while i was eagerly anticipating the animal shifter theme, there isn't enough done with it; despite the clumsy infodump at the start it seems mostly to be a gimmick. secondly, the male pregnancy bit is seriously getting on my nerves by volume 4; it comes complete with sex organs changing into female ones. if i wanted to see that sort of thing, i'd be reading hentai, ok? there is just too damn much of it; nearly everyone is having babies, and those who're not, are talking about having babies -- which is another thing that bugs me. i don't really want to have a lot of babies in my BL either; babies are the complete opposite to "sexy" for me.
compared to those issues, the art isn't a big problem. it started out striking me as fairly unattractive, but it gets better; except for the hands which stay spidery-ugly the whole time. the animal art is good right from the start; kunimasa's jaguar form is beautiful, and norio's alter is cute.
storywise, i don't know why everybody thinks it's so original. it's just done on a somewhat larger scale than the typical BL manga, with everyone being connected to everyone else in some way -- which is what makes it a soap. and it seems to me quite typical soap: lots of trumped up misunderstandings, hurt feelings, denied feelings, seemingly unreciprocated love, love triangles, plus the occasional sheikh thrown in for exotic appeal (ok, so it's original that his name is "seth" and that he's blond, snrk) -- and hey, we have some men who look completely like women, so it really is no different from a hetero soap. the animal gimmick is used as a stand-in for social differences between people. instead of manual labourers, here bats are looked down on. instead of romeo and juliet from feuding families, we get a snake and a mongoose who're "natural enemies". it's also very standard BL in its seme/uke power dynamics, and doesn't break from those; heck, it feminises some of the uke more than most BL; it's all "my wife" and "my husband" stuff. which really, really, really bugs me. girly crybaby uke are bad enough, but turning men into actual women should be a no-no for BL.
while it doesn't strike me as amazingly original, as a soap it is quite well done, with decent plotting and resolution of problems not dragged out forever. and because the characters are all connected and reappear throughout the volumes, it's easy enough to invest emotions in some of them.