Mr. Takeho Ishiyama and Mrs. Akiko Ishiyama are Yumi's and Hiroki's parents from Kyoto, Japan. They are of Japanese descent and are usually loving parents. They often worry about their daughter and her late nights out as seen in A Great Day and Exploration. This theme is revisited throughout the series. Their relationship is, at times, rocky, and they can be seen bickering during the series. They even once temporarily separated in Laughing Fit, but they get back together thanks to Yumi and Ulrich.
In The Chips Are Down, Mr. Ishiyama had lost his job and the family almost moved back to Kyoto, Japan, but he found another job and they were able to stay in France.
They have had a rather shaky marriage, often getting into heated arguments. Mrs. Ishiyama has commented that she shouldn't have married a man from Tokyo.
In the French version of Code Lyoko, Mr. Takeho Ishiyama's voice was either provided by Mathieu Moreau or Frederic Meaux. Mrs. Akiko Ishiyama was either voiced by Alexandra Correa or Nathalie Stas. The information as to who plays who is disputed. In English, he was played by David Gasman. In English, she was played by Jodi Forrest.
|Jeremie Belpois | Aelita Schaeffer | Odd Della Robbia | Yumi Ishiyama | Ulrich Stern | William Dunbar|
|Sissi | Jim Morales | Suzanne Hertz | Anthea Schaeffer | Mr. Delmas | Laura Gauthier | Franz Hopper|
|Kiwi | Herb Pichon | Nicholas Poliakoff | Amelia "Milly" Solovieff | Tamiya Diop | Hiroki Ishiyama | Johnny | Takeo and Akiko Ishiyama|
|X.A.N.A. | Monsters|
|Professor Tyron | Ninjas | X.A.N.A. William|
|Jean-Baptiste Pujol | Theo Gauthier | Emily LeDuc | Taelia | Samantha Knight | Samantha Suarez | Heidi Klinger | Mathias Burrel | Magali de Vasseur | Claire Girard | Brynja Heringsdötir | Patrick Belpois|
|X.A.N.A. Aelita | X.A.N.A. Odd | X.A.N.A. Yumi | X.A.N.A. Ulrich | X.A.N.A. Franz Hopper | X.A.N.A. Anthea Schaeffer | Jeremie Clone | Aelita Clone | William Clone | Subdigitals|