Quiz

He is skilled at playing shogi, having the Shogi Certification in 3rd Class. He appeared in several Shogi events on Niconico and appeared in a Pokémon game event on Niconico as well.

In the third Seiyu Awards held on March 7, 2009, he won the award for best rookie actor for his portrayals of Accelerator in A Certain Magical Index, Shin Kanzato in Persona: Trinity Soul and Ryuji Kuhoin in Kure-nai, when he graduated from university.

He's the host of a radio program about gaming called RADIO 4Gamer from 2010 to 2015 then the program changed its name to RADIO 4Gamer Tap and continue on with Okamoto being a host.

In the fifth Seiyu Awards held on March 5, 2011, he won the award for best actor in a supporting role for his portrayals of Takumi Usui in Maid Sama!, Eiji Niizuma in Bakuman, and Accelerator in A Certain Magical Index.

In an interview held at the Anime Expo, when answering what inspired him to become a voice actor, Nobuhiko mentioned that he has always been a big fan of Slam Dunk and thought the character Rukawa was really cool, so he wanted to be like him.