It is popular belief that
diamonds are a girls best friends. WRONG! That is completely incorrect. Let me tell you why.
What girls need to get noticed, is to stand out from the crowd. A kimono is the best thing to do this. When a guy is walking down the street, he's only going to look around if he sees something interesting. To get noticed girls used to wear more and more weird and wonderful clothes, vivid colours, etc. But that's old hat now. Everyone does it. So a guy will never give that more than a brief glance. Kimonos embrace all of these things, though.
They often use distinctive colours and patterns. However they are exotic pieces of clothing, even in Japan (they aren't worn very often). Wearing rare clothing that is beautiful will always get you noticed. And if you can get someone to notice beautiful clothing, the normal response is to look at the person wearing it, to see if they are equally pretty. For example, geisha are rarely passed by in the street without being looked at by a fair number of people. When they are wearing normal clothing, they blend in. But when they are wearing bright kimono and obi, they look exotic, almost heavenly.
The second benefit is that kimono can make girls look better than they really are, as they enhance a girl's beauty. Like jewelry, a beautiful kimono will rub off on its wearer. The only real asset you need to look good in a kimono is not to be fat (I mean sizably fat). Apart from that, other assets aren't necessary as a kimono is fairly concealing and hides quite a few defects.
As simulacron3 mentioned, men do wear kimono too, though they tend to be worn by the older generations or during special events. They are very similar to women's kimono at first glance, though the cut differs.
Both men and women wear Hakama trousers for festivals and religious occasions.