Mayumi

Mayumi is shy, sincere and uncomfortable expressing romantic feelings directly. She relies on friends for advice when deciding how to approach Jonouchi rather than simply confessing to him.

Her feelings are earnest, and she puts considerable effort into preparing a personal gift. The blank puzzle appeals to her because it allows her to communicate privately through something Jonouchi must actively solve.

Mayumi is also vulnerable to embarrassment. The possibility of her private feelings becoming public causes significant distress when the puzzle becomes involved in a classroom inspection.

Mayumi is an ordinary Domino High School student with no supernatural powers or established Dueling ability.

Her principal role involves the handmade message puzzle she prepares for Jonouchi. The puzzle itself originates from Sugoroku's game shop, where the blank surface allows Mayumi to create a personalized confession.

No Duel Monsters Deck or signature card is established for her.

Mayumi approaches Anzu and Miho because she wants to give Jonouchi a love letter. The girls enlist Yugi Mutou, who takes them to his grandfather's game shop in search of an appropriate present.

Sugoroku recommends a blank jigsaw puzzle. Mayumi writes her message on it, creating a gift that Jonouchi must assemble to read.

The puzzle subsequently becomes important during a classroom inspection conducted by Chouno-sensei. Yugi protects Mayumi's privacy when the teacher attempts to expose the message, leading into Dark Yugi's Shadow Game against Chouno.

Katsuya Jonouchi is Mayumi's crush and the intended recipient of her puzzle message.

Anzu Mazaki helps Mayumi decide how to approach Katsuya Jonouchi.

Miho Nosaka also assists Mayumi with her romantic problem.

Yugi Mutou helps Mayumi choose a present and later protects the privacy of her message.

Sugoroku Mutou suggests the blank jigsaw puzzle that Mayumi uses for her confession.

Chouno-sensei attempts to expose Mayumi's private message during a classroom inspection.