Mario Sis.

A girl so enormously in love with the Mario Bros. that she would do anything to be adopted.

Mario Sis.: Hi Luigi, can I be your little sister?

Luigi: I'll have to check with Mario Mario first, cause I'm nothing but a lame sidekick that can't really make my own decisions.

Mario: Well you can be a Mario Sis. if you show us how to kick Bowsers ass once and for all.