In "Planet Namek", a Four-Star Dragon Ball can be found underwater. This is likely a reference to the story of Dragon Ball Z, in which Vegeta threw the Four-Star Dragon Ball into the water after killing everybody in a small village to obtain it.
Some characters state are taken from their most popular sagas instead of their current ones at the moment the game was launched. This includes Yusuke and Hiei (from Dark Tournament Saga), Ichigo, Aizen and Rukia (from Aizen Saga) or Goku and Vegeta (from Cell Saga) for example. Some others are taken from their current anime saga at the moment instead of the current manga saga. This includes Joseph Joestar (from Battle Tendency Saga), Toriko and Zebra (from Four Beast Saga) or Gon and Killua (from the Chimera Ant Saga).
Although trailers for the game show Yusuke Urameshi performing his Victory Burst "Spirit-Gun Mega" while in his Demon Form, he is unable to use his Victory Burst in his Demon Form in the final game.
Files found on the game disc suggest that there was originally supposed to be an in-game announcer that would narrate character introductions, combination bonuses, victory bursts, and various other aspects of the game.
Data for Jotaro Kujo and Dio from JoJo's Bizarre Adventure, Dai from Dragon Quest: Dai's Great Adventure, and Yoh Asakura from Shaman King can be found in the game's data. It is currently unknown whether they were planned as DLC, or were originally intended to be included in the game, but were later removed.
Characters that share the same voice actor will have special dialogue when paired against each other. Examples of this are Monkey D. Luffy and Luckyman (both voiced by Mayumi Tanaka), and Ichigo Kurosaki and Seiya (both voiced by Masakazu Morita).