Mayumi is an Investigateen in Phillip Fathom, Deep Sea Detective and sister to Investigateen Tony. She is critical of The Fishwife, believing that the villain could be a more responsible example of women in the field of science. She is played by Kate Micucci.
Her brother Tony claims she is a know-it-all. She's also shorter than Tony.
- Love on the Rocks (TAH #176)