Shinohara Ryoko made a special guest appearance at the 30 y/o Budokan concert
https://www.barks.jp/news/?id=1000163135
Barks wrote that it was the 5th straight year for ayaka to perform at Nippon Budokan on Boxing Day . That 'record' has already broken in that Nippon Budokan will undergo renovation from next Sept onwards
ayaka performed 16 songs at the concert