CyberConnect2 tried to pitch Tail Concerto 2 to Namco Bandai, more than once actually. That didn’t go so well in 2000. During a CEDEC presentation, the Solartorobo development team said the proposal was thrown in the trash right in front of the CyberConnect2 staff.
Hiroshi Matsuyama, CEO of CyberConnect2, and his team went back to the drawing board with a new proposal in 2003. And again in 2004. Bandai rejected Tail Concerto 2 twice because they wouldn’t believe it would sell. Concept art for the two ideas are all that’s left of Tail Concerto 2.
After the 2004 rejection CyberConnect2 moved on and started planning Solartorobo, a spiritual successor for the Nintendo DS.