Anzu is the childhood friend of Yugi Mutou. She becomes a good friend to Katsuya Jonouchi and Hiroto Honda, though she is not fond of them at first. In the first series anime, Miho Nosaka is also one of Anzu's friends. Anzu does not usually play games with Yugi and his friends, though she is once shown beating Jonouchi. In the manga, especially in the beginning, Anzu has a spunky, tomboyish personality, and in the first chapter, frightens Honda and Jonouchi into leaving the room after they bully Yugi. Anzu possesses a very kind-hearted, strong-willed, and supportive personality. In the Duel Monsters anime, she and Honda, are basically cheerleaders for Yugi and Jonouchi whenever they duel, but she has proven herself adept at dueling as well, and usually keeps up with the going-ons of a duel. She is more feminine, polite, and has a stronger sense of faith and friendship for her group of friends, often serving as the mother/sister figure for the boys. She is known among fans of the Duel Monsters English anime for her "friendship speeches."

Anzu is athletic and holds jobs to save money in order to attend a dance school in New York City. In the beginning of the series, she is revealed to be working at "Burger World". By Volume 4 in the manga, Anzu is fired from that job for punching a customer who had pinched her buttocks. She gets a job at KaibaCorp afterwards and encounters her friends at KaibaLand. In the Toei anime, Anzu, Honda, and Miho work at Burger World, with Miho and Honda working to support Anzu. Once Burger World closes, Honda and Miho work for a beef bowl restaurant. In the opening scenes of the 1999 film Yugi and his friends discover that she works at "Duel Monsters Center," a Duel Monsters parlor. She already knows Shōgo Aoyama, a regular of the parlor and Yugi's neighbor.

While responding to a fan mail asking him why Yugi and Anzu are not in a romantic relationship, Takahashi stated that the relationship between Anzu and both Yugis is "pretty much a love triangle." He added that Yugi and Anzu "always" act in a "very careful" manner in front of one another, so they cannot admit their feelings for one another. Anzu's first Deck is a Fairy Deck. It focuses on Light-Attribute Fairy monsters, and spells to enhance them. Her second Deck is a Spellcaster Deck. Almost all the cards are devoted to the Spellcaster theme, like Fire Sorcerer, Maha Vailo and the Dark Magician Girl because of her one-sided love with both Yugis. She duels once in the manga and three times during the course of the second anime series. During the Virtual World arc, she wields a deck that parallels Yugi's Spellcaster deck, albelit with a more feminine touch.