After you meet Ishizu for the first time in her pleading for you to save the world, go back to your house and save. Then go to Kaiba Corp. where and intriguing conversation occurs between Rebecca, the US Champion, and the Kaiba bros. Eventually, you will be forced to face her because Kaiba feels she doesn't have the skill.

Note: When you battle Rebecca, she will have a lot of Dream and Light Monsters, so keep a lot of Fiend and Dark type monsters handy! ^_^

Vote appropriately please!