Is it possible it is a "soft tennis" racquet?
I see a Yamaha TZ850 on the big Japanese auction site with a similar wedge-shaped hoop, though the shaft is longer than your specimen. Classified under Tennis>Rackets>Soft Type. It has a similar "badge" at the top of the grip.
Last edited by Love50; 10-02-2012 at 02:26 PM.
Reason: Added information