Rave girl
Rave girl is a character from the pop'n music series. She look much like Mary, except her entire body is black outside from an outline of her body, which is a different color from game to game.
Very little information is known about this character, other than the fact that she likes to dance and often goes to club to do so.
Her character's font is done in the same style as the names of songs in the early beatmania games, which contained many of the ideas, concepts, and staff that Pop'n Music would later inherit.
Song appearances (this is not complete):