The final was held at Saitama Stadium on Saturday, Oct 15. The score was at 1-1 after 120 minutes, and Urawa beat Gamba Osaka 5-4 in a penalty shootout to win the title.
National Stadium had been used for the J League Cup final, but it had to be demolished in 2014, to build a new one for the olympic in Tokyo, 2020.
Saitama Stadium was chosen to be replaced in the meantime, although it is the home of Urawa Red Diamonds. Saitama Stadium has been used for domestic plus international big soccer matches many times. That could be why.