Kairi Tanaga appeared in the Batman: The Animated Series episode "Day of the Samurai". She was the star student of Sensei Yoru, who was also the martial arts instructor of Bruce Wayne.
At the arcade Cheezy Dans, the video game Max drags Zander over towards is Sentries Of The Last Cosmos, which was the title and main plot of the season two episode 'Batman Beyond: Sentries Of The Last Cosmos' (2000).