Its literal meaning, however, is "a being at puberty age who is neither quite adult nor child." It is a word that came into use a decade ago among Japanese middle aged and parents to describe the awkward stage their children were going through during middle-high school.
The word itself debuted in foreign vocabulary by means of the Gothic and Lolita Bible vol. 1, where it was used to describe the general feel of Plastic Tree singer Ryutaro's somwhat offbeat, questionably mentally un-wholesome childishness. The foreign Gothic & Lolita fanbase picked up on the word and mistook it for the style name, eventually equating it with the "oojisama (prince)" look.
It is recognized as a fashion outside of Japan, but not as such in its own country of origin.