Hi, I'm looking for a manga with the following criteria:
-the female lead was rejected by her first love (she has to be a bit naive at the beginning of the story)
-after the rejection she becomes more cold-hearted/ indifferent to bishonens. Or on contrary an easy women (she doesn't care with who she sleeps, she changes partners like underwear and she no longer believes in love).
Prefered if: it contains smut

Maybe...
Silver (FUJITA Kazuko)

It doesn't have smut, but that also describes Skip Beat
I second Silver (FUJITA Kazuko)!

________________
As they played the game...I waited for someone to call "onigiri." But no one called. I was very little then. I had almost forgotten about that. [...] But they knew...there would never be room for an onigiri...in a fruits basket.
-Tohru Honda, Fruits Basket

i second skip Beat (she more like ignore all bishounen and go to her own wonderland)

I third Skip Beat - that's her completely.

Money Ace X is perfect but it doesn't contain smut and the ending is quite ambiguous

kimi no sei she actually doesnt get rejection , but theres something that makes her the way she is ..


________________

Oh, the girl who doesn't look for love and changes partners all the time... That would be Velvet Kiss. Although that's close to hentai...

________________