Comedy Echii - The Idol Pretender
http://www.mediafire.com/?3n7lertoyosx9muDrawing it's quite good, but story it's mmm... silly, mostly for all the idol stuff, but well, that's just my own opinion about it.
Still I really like to see some slow mental changes along with the physical change, this thing has it, the protagonist doesn't just jump into womanhood
So, chapters 1 to 3, I don't know if there have been any new translations yet
Oh, this may spoil things a bit, but there is "supposed to be" a trap in chapter 3, I say supposed to be as since this is a Echii comic we don't get to see no genitals