The Kisarazu High School Mandolin Club has given the 43rd regular concert in April 2012 in Kimitsu.
I have found several youtube videos of this concert.
One of my favorites is the following – Dance Suite Nr. 2
Another interesting videos shows each instrumental goup of the orchestra with a piece by this instrumental group alone to demonstrate the instruments of the mandolin orchestra:
mandolins, mandolas, mandocellos, double basses, guitars:
I have collected all videos in the following playlist:
http://www.youtube.com/playlist?list=PLC9DF3E78F3116B19
Additional Information
Wikipedia about Kimitsu: http://en.wikipedia.org/wiki/Kimitsu,_Chiba
Wikipedia about Kisarazu: http://en.wikipedia.org/wiki/Kisarazu,_Chiba