Japan Cup (Japan)

Quick Premiers List :

2009 - ?. 2011 - ?. 2013 - ?. 2015 - Tokyo.

General :
The Japan Cup was a tournament-style competition intended to be held every two years.

Timeline :
2009 - The Narita Cup evolved into the Japan Cup.^[source]
2011 - ?.
2013 - ?.

2015 :^[source]
This was the 4th time this tournament had taken place. (presumably not counting previous incarnations as Sugadaira and Narita Cup)
The Japan Cup was held at Chiba.
Participating clubs were (complete) :
 - Eastern Hawks-R246 Lions,
 - Komazawa,
 - Senshu,
 - Sendai Port,
 - Shonan (5th),
 - Tokyo and
 - Tokyo Bay-Miyazaki (6th).
Grand Final - Tokyo defeated Komazawa.