Saitama Super Arena (さいたまスーパーアリーナ, Saitama Sūpā Arīna), currently known as GMO Arena Saitama for sponsorship reasons is a multi-purpose indoor arena located in Chūō-ku, Saitama, Saitama Prefecture, Japan. It opened preliminarily on May 5, 2000, and then was officially opened on September 1 of the same year. Its maximum capacity is 36,500.

I believe that this stage is referencing its appearing as a recurring filming location in the Kamen Rider series since Kuuga.