Mustache Girl is a 13-year-old girl after Hat Kid's time pieces. She is very heroic and has a strong sense of justice and what's wrong and what's right. She wants to use the time pieces to get rid of all bad guys from the world, which is a horrible idea due to the fact she would be tampering with time. She tends to mess with the mafia and other criminals, envisioning herself as the hero. She will stop at nothing until she becomes the hero of this world. She also has a fear of being alone.