Masao is a character in the Yu-Gi-Oh! GX manga, and a childhood friend of Syrus Truesdale. He appears in Zane's flashback to his and Syrus' childhood, while he watched Syrus Duel Chazz in the first round of the Duel Academy Tournament Finals. Masao Summons "Angel O7", which Syrus destroys with "Trap Hole". Feeling bad for his friend, Syrus allows Masao to win the Duel despite having a card that could defeat him in his hand.