In the summer of 1995, Okada participated in Johnny's Pre-School, part of the NTV program Tensai, Takeshi no Genki ga Deru Terebi (天才・たけしの元気が出るテレビ!!).
In a Shounen Club Premium interview on May 7, 2009, he revealed that it was the Japanese drama Kisarazu Cat's Eye that caught the attention of viewers and directors, and made them aware of his acting ability.
In the movie he portrayed a young college student torn between his love for a lady twenty years his senior and the views society has on these kinds of relationship.
In the movie, Okada portrayed Sōza, a samurai uninterested in killing his enemy and focused on what he could do today to be a better person instead.
[10] Later, he was involved in movies such as Flowers in the Shadows, portraying a young man in debt because of pachinko,[11] and Otonari (おとなり), an unconventional love story between two neighbors who have never met each other and only follow the other person's life through the sounds they hear from the other side of the wall.
The film follows the journey of a kamikaze pilot named Kyuzo Miyabe, a man described as a coward who volunteered to die for his country.
[16] In an interview on Shounen Club Premium, Okada said that when he was little, whenever his name was called up to read something in class, he would feel like vomiting and purposely avoided school on those days.
Office vice-president and former V6 co-member Yoshihiko Inohara asked for discretion, and to wait for an official comment by the person himself.
[23] In 2010, Okada had reported in a press conference that he is certified to teach Jeet Kune Do and Kali in Japan, the latter was used by him as his main martial art when the SP series was filmed.
Okada participated for the first time in a public match in the International Brazilian Jiu-Jitsu Federation (IBJJF) World Master 2023 in Las Vegas, USA, on 31 August 2023, in the Master 3 Brown Belt Light Featherweight Division,[26][27] winning his first round, but losing on the quarterfinals against Andrew Steve Slackta.