A young and naive person who is, often times, confused and angry at the world. On the exterior, this person will present rigidity, boldness, and cynicism of people in general. On the interior lies a soft, kind, caring, sensitive being who may resemble a huge teddy bear relative to her personality. These sorts of people are generally spontaneous in though and tend to relish unorthodox practices i.e. wrestle as a female, talk about penises and vaginas rather openly, etc. One could call a "Hiroko" as a heretic of societal norms.
Further, a "Hiroko" will fall for people named "Erik" (yes, with a "k") and will dislike people named "Scott", which is rather odd because on Urban Dictionary, Scott is typically a nice person. But that just goes to show the non-conformist trait of a "Hiroko".
She is such a hiroko.
Hiroko is also often used in the present-progressive form and as a verb. i.e.
I am hirocking (hee-rock-ing) my new hairdue.
Dude, that person is SO hirokoed.