[3] After graduating from a local technical high school, Ōsaka moved to Tokyo with a friend who also wanted to be a voice actor, and studied the basics of acting for two years at Nippon Kogakuin Hachioji College.

After graduating, Ōsaka attended a voice actor training school, passed the additional audition for the agency Early Wing, and made his debut in 2010.

Yukio Nagasaki, who saw his performance at the audition, said he thought that he could become the face of "a new generation of male voice actors in main roles".

At the first post-recording, he was nervous and was encouraged by his co-star Tomokazu Sugita, who told him, "We will work, so you can concentrate."

[4] Ōsaka announced his marriage to fellow voice actress Manami Numakura on October 23, 2019.