Go! Baajinaru Hanayuki

It all starts when Tomoe's hair gets caught in Kouga's button. Like a red-string of fate they're tied together. Through a twist of that fate Tomoe is forced to work in a house of prostitution lead by the Yakuza (Japanese gangsters/mafia), and who might be one of the Yakuza heads, but Kouga.
Funny and dramatic, but more innocent than you think. ^_~