Nagai pleaded with Tanahashi backstage after his match to be in the BOSJ as the replacement for DOUKI https://www.njpw.co.jp/card-result/639811
Then, at the end of the show, with the support of the fans in attendance, he asked Tanahashi again. After checking that Nagai wasn't just happy to participate but that he wanted to win, which Nagai confirmed, Tanahashi confirmed that Nagai would be in this year's BOSJ. https://www.njpw.co.jp/card-result/643838
by NickyAfro