Mayumi (まゆみ Mayumi) is a character in the Toei Yu-Gi-Oh! anime. She wanted to give a love letter to Katsuya Jonouchi.
Mayumi asked Anzu Mazaki and Miho Nosaka about Jonouchi and they questioned her liking in him. Still, they asked Yugi Mutou for help choosing a present, as Yugi was Jonouchi's friend. Yugi took them to his grandfather's game shop and his grandfather, Sugoroku Mutou gave them a blank jigsaw puzzle, telling Mayumi she could write a message on it and give it to Jonouchi to figure out. He also stated it was how he got Yugi's grandmother to like him.
Later, Mayumi slips the present into Jonouchi's desk when they get to class. But when Jonouchi finds it, the teacher Ms. Chono, takes it and says she will figure it out, then read the message. Anzu stands up and says that Ms. Chono shouldn't be reading other people's messages and says she was the one who gave Jonouchi the gift.
Ms. Chono later called Anzu into her office telling her it was against the rules to bring something like that to school. Anzu complains the rules are too strict and says she will make a petition to lessen the strictness in the school rules. But, a few bullies write bad words over her signs and break her petition board. Yugi and Jonouchi support her and Jonouchi fights the bullies. Ms. Chono sees them fighting and calls them to her office. She says that they were in trouble. Yugi, Anzu, and Jonouchi complain it wasn't their fault. Ms. Chono lets them leave and calls in the bullies. She thanks them for doing what they did to Anzu and pardons them.