The main plot of the games covers about everything in the regular series up to the end of the Hallelujah Land arc. This game also features a scenario involving the Train and Dark Yasha.

As the title suggests, the game features the nine main characters, who must work together and merge to produce various combo moves. Only three of the nine characters can take part in battle at one time, so players must select three characters and strategically "blend" them to produce the best combos.

Apart from normal attacks, the battles feature more than a hundred different types of Bo-bobo-esque "fusion moves" and "side-splitting" moves. Among the formation moves are "Tokoroten Magnum" (performed by Bo-bobo and Tokoro Tennosuke) and "Hello Baby" (performed by Dengakuman and Torpedo Girl). Characters also have unique individual moves that are more powerful than normal attacks -- for example, Bo-bobo's "Sexy Beam" and Softon's "Jamaican Passion". All these moves incorporate humor, irony, and defy expectation. Some moves are incredibly elaborate but do nothing, while others look completely harmless but deliver a massive blow.

The game also includes a number of off-the-wall mini-games bursting with Bo-bobo humor, such as a parody of Hudson's famous shooting game, "Star Soldier", titled "Star Boldier".