Bow is the princess of the Boos in Boo's Mansion. She will befriend Mario and join his party in the game Paper Mario. She can shield Mario by making him disappear in both battles and non-battles.
In Paper Mario
Bow sends her assistant Bootler to talk to Mario to go through Forever Forestto reach Boo's Mansion. After going through the spooky forest Mario and party arrive at Boo's Mansion. Bootler appears at the front door and says that Lady Bow wants Mario to solve puzzles of the mansion to reach her room at the top floor. After doing so Bow reveals herself to Mario and party and says she owns the mansion. She also says that she needs her help. She shows a cage containing the Star Spirit Skolar. She also says that the Star Spirit managed to escape Tubba Blubba's Castle and she found him. She joins Mario as a member and uses her invisibility powers to help out. They manage to go through the castle and run from Tubba Blubba with a key. They unlock the door to Windy Mill and discover Tubba Blubba's Heart has been separated from his body. After the body and heart reunite Tubba Blubba is an easy opponent. After the short battle Bootler gives Mario Skolar and Bow decides to stay with Mario on his adventure.