Anna passed as a participant of the World Duel Carnival so that she could get her revenge on Yuuma. While in Elementary school she was a tough girl, though she had a soft side and had a crush on Yuuma. Before she transferred schools, she wanted to confess her feelings to Yuuma, but he never showed up.
When Anna met Yuuma again, she repeatedly tried to blast him with her cannon. However, due to Yuuma's suggestion, she decided to get her revenge by Dueling instead.
At the end of the duel, it is revealed that the boy Anna had feelings for wasn't actually Yuuma Tsukumo but Yuya Tsukune. Since Anna did not officially enter the tournament, she could not give Yuuma a Heart Piece for winning the duel. However, in the end she did develop feelings for him, first loving then hating him after hitting her head while thinking about him.
When speaking, Anna uses "ore" (俺) when referring to herself (supporting her tough girl attitude), a pronoun that is dominantly used by males and very seldom used by females (who are most likely tomboys in nature). Anna is also shown to be quite hotheaded and reckless, often rushing into things without thinking the situation through. Astral calls her Dueling style very reckless (using up her entire hand in the second turn) but also very calculated (being able to push her opponent in a corner in only the third turn), which coincides with her personality.