This fashion is not popular anymore, however. They say the manba style had a short revival 2004, but died again at the beginning of 2005. You still see some of them though, gals and boys, around Shibuya. But meh:
I think the manba-style is very interesting. I'd never in my life want to look like than myself, but I DO admire them for being as brave as they are. They are definitely going against old japanese standars, knowing that when doing so, they'll get hated by EVERYONE (yeah, just look at the majority of the posts here). What the manba-thing was really about from the beginning, was a revolt against the traditional view on femininity in Japan. The girls tanned their skin (because female ideal was white skin), they exaggerated their make up to look more hideous than pretty, they wore neon color clothes (to stand out in a gray crowd), and they were loud, outspoken and rude. They annoyed the hell out of people - off course! It was like a revolution that went faar beyond simply creating a new type of fashion. When the guys joined up, they created their own revolt - and did what guys aren't supposed to do: Make up, try to look 'cute', wear feminine OR female clothes. These guys don't exactly do this to become popular, you know... If you choose to become a manba/centa-guy, you do it to stand out, to be different, and you do it knowing most people are gonna hate you.
In difference from a lot of todays 'subcultures', such as punk, goth and lolita-fashion, that are all subcultures that have been copied from an original state and commercialized for the heck of it, the MANBA-style is a new, and very modern subculture that's actually got some meaning behind it in it's current state. It's a modern sort of punk, I'd say... The similarity to punk (as a movement and style, not as music) is big;
Punk shocked England in the 80s (end of 70s), the kids were rude, horrible, anarchistic, dirty and wore clothes that were considered 'trash'. This was going against the old english standards and morals.
The manbas do the same today, but in Japan.
If they want to do that, if they want to look like that, let them. I admire them for being brave enough to do it. Simply saying things like 'GAY' or 'UGLY' seems a little... unnecessary? Off course they're no beauties... they're not trying to be. They want to shock people by exaggerating and mixing what is considered 'cute' in the modern Japan, turning themselves into 'monsters' of a modern world.
... the only annoying thing about them is that they talk on their cell phones VERY EXTREMELY LOUD wherever, whenever.. even on trains.. which is... annoying... (>_<)