Mary Jane Watson (aka M.J.) is the love interest of Peter Parker (aka Spider-Man) in the Spider-Man universe. She grew up in a broken family with an abusive father and put on a "party girl" attitude to hide her distress. She was an acquaintance with Peter Parker due to the fact that her aunt Anna was neighbors with the Parker family. Her feelings towards Peter have been described in many different ways by many different writers and is completely up to interpretation at this point. Mary Jane is portrayed by Kirsten Dunst in the Sam Rami's Spider-man trilogy.
She works as a model/actress and often finds herself in cliched position of " Damsel in Distress". Not much can be said about the girl, her personality changes with the ebbs and flows of many writers. It is confirmed however, that she is a natural redhead.