And about Kasumi, we can assume that she is straight and before going out with Kashiwa and that she never dated a girl, you people really thought that she would not like to marry and have children? that she would not prefer that Kashiwa stayed a man? how the only good relationship could be ruined when she said that despite the fact that she would like those things she still want Kashiwa to change sex? there are people out there who would take advantage of the situation to make their partner not change sex, the fact that Kasumi still wants Kashiwa to change sex just show how much she love her.
Sure this is not one of the most realistic mangas, but the fact that there is people who didn't like what Kasumi said just shows that the fluffy and happy yuri where not bad happens and everyone accept lesbians, is corrupting your judgment about how things really work, sure there are places where gay are accepted and can have lifes like that, but it's not the case in most of the world, especially Japan.
I hope that my english was good enough so that what I wrote makes sense...
Just wanted to say that Kasumi is the character I liked most in the whole manga. I totally understand her saying she prefers Kashima staying male or wanting to have kids and all. The thing what I had problems with were the words "If you had the surgery we'll eventually have to break up." It may sound naive but I believe if you really love someone you would stay together with that person even if he/she had a sex change. In that way I really find what Kasumi said later on to Kashima in the diner that much more satisfying.
And yes, your english was more than good enough. I was born in America and mine isn't nearly that good :x