rofl, I never heard about hitomi supposedly being a lesbian. and somehow it's negative? *backs off* lol
and about Ayu, I think her smoking isn't a rumor. she does smoke, unless you are in complete denial & ignore several photos with her holding a "pen"
her being bossy it's not obviously known wheter it's true or not, but she has said she likes to be in control in everything about her career so I'm sure she's bossy to an extent. often female stars of her caliber can be "difficult"
bossy is a nice way to put it tho, there are plenty of rumors that behind the scenes Ayu's a full-blown tyrant who fires people at whim & demands a lot.
I haven't heard that many rumors about jpop stars in general tho.
there are some flying around about the idol groups, like H!P & JE. how they actually themselves make a lot less money than "regular" artists & how their private lives are being controlled by the companies with long lists of rules.
I've heard a rumor about TK, the rumor is that he sleeps with all the female singers he works with. with singers like hitomi , namie , ami suzuki and etc. tho TK has married two of the singers he has worked with, so obviously there has been something going on in the studio besides just work ...