Blue (ブルー Burū) is a character in the Toei Yu-Gi-Oh! anime. Her role in the series replaces that of "name unknown" from the manga.
Blue, along with Red and Black were three people at Kaiba Land, hired by Seto Kaiba to play the Stardust Shootout game against Yugi Mutou and his friends.
Kaiba rigged the game so that the players on his team had real lasers that caused fatal electric shocks when fired while Yugi and his friends were given toy guns. Yugi, Hiroto Honda, Katsuya Jonouchi, Anzu Mazaki, and Miho Nosaka) participated in the game. Miho's timidity led to the downfall of the three KaibaCorp employees.
Although it may be a coincidence, in the 1988 OVA Violence Jack: Evil Town there's a blonde-haired, blue-eyed male-to-female transsexual, named Blue. Blue was a villain in both the anime and manga of Violence Jack, who killed several characters with ease. The Yu-Gi-Oh! franchise has had many similarities to other works by Go Nagai, the author of Violence Jack.
This summary is currently incomplete.