—Yumi to Jeremie
Yumi Ishiyamais a black haired tomboy-Japanese girl with a taste for American Gothic. She is the oldest of the gang. She can become a geisha-like warrior with fan that can block X.A.N.A attacks and can use psychic powers. Besides her mind powers, she can also attack with her metallic fans. She is one of the main protagonist in the Code Lyoko series.
Yumi was born in Kyoto, Japan and moved to France with her mother, father, and younger brother. She is very respectful of her Japanese heritage and culture and enjoys most of the customs as well. While attending Kadiac Academy, she didn't know many people and didn't have any friends. She lated befriended the other Lyoko Warriors after she and Ulrich Stern were attacked by X.A.N.A. during a training match. She often gets angry when people mistake her for being Chinease rather than her true heritage of Japanese.