He appeared on the "Entertainment Industry's Underwater Swimming Competition" section of the show Quiz Present Variety: Q-sama!!

During a two-hour special aired in September 2005, he broke the 115 meter Japan record previously set by Yasuda Dai Circus' Dancho Yasuda for DNF (dynamic apnea without fins) diving, establishing the Japan DNF record at the time at 116 metres (381 ft).

In that same period, Nokubo formed the band Shūchishin with fellow obaka tarento Takeshi Tsuruno and Yusuke Kamiji, and they made their CD debut with the release of their eponymous single 'Shūchishin' in April 2008.

[8] On 1 April 2010, his profile and blog were deleted from Watanabe Entertainment's official website, making it clear he was no longer with the company.

In June 2010, he joined the acting group Ai no Katamari (renamed ai-kata in 2011), formed from Gekiden Taishū Shōsetsuka.

He also started a personal Twitter account and gave Breakpoint Inc. the responsibility of accepting his fan letters, as the business was a partner of the acting group.

In January 2012, Nokubo was treated as in the public sphere for the first time in three years at the production press conference for the stage play Legend of the Galactic Heroes Chapter II: Free Planetary Alliance, which was performed in April 2012.

[10] He was also team captain when he was in his third year at Kinshin High School, and he was included on the draft candidates list of the Chunichi Dragons.

[10] He attended high school with Tomoyuki Oda (former Hokkaido Nippon-Ham Fighters' inside fielder) and Masaki Hayashi (former Hiroshima Toyo Carp pitcher), who were both his senior by two years.

Nokubo has stated multiple times in television interviews that he attended Júbilo Iwata games and that he was, in particular, a fan of Masashi Nakayama.

[11] Nokubo has also spoken several times about his experience as a doorman at Prada as a temporary part-time job which he had before starting his acting career.