"Maywa Denki" is a musical band and they also creates their own instruments for the concert.
All the instruments are electrical and they have really fun sounds. The way to play these instruments are also unique.
http://www.youtube.com/user/maywadenki ---- This is their Youtube channel. A lot of the videos are demonstrations on how to play their instruments.
By the way, you could purchase their instruments on Amazon and Ebay.