From the studios of NanaOn-Sha (PaRappa the Rapper) and iNiS J (Gitaroo Man) comes a newly announced project under the title Project Rap Rabbit. The information available so far is sparse, and comes via an official site and official twitter account. What we know for certain is that it is a "story-driven rhythm-action adventure," according to the official twitter, not unlike the studios' most well known titles. The site only plays the video that can be found below:
Based on what we've seen, the game will likely star the rabbit featured in the art. It will likely take place in China, though the time period is a mix of both old and new. Classic attire and architecture are the most prevalent in the image/video. However, one character rests on a motorized scooter, mechanized turrets line the edge of the large building, and flying drones and UFOs carry on in the background.
The title may be a placeholder, as game titles that begin with "Project" are often changed later in development, though it's still only speculation. Hopefully we will see more at this year's E3, if not sooner.