Masaki Kawanabe was such great friends with fellow "Tokyo Majin Gakuen" seiyuu Takayuki Ishiguro (original VA of Yuuya Daigo) they shared an apartment together. Kawanabe said of Ishiguro: "He's such a master cook, I was never left hungry."

Some of Kawanabe's comic artwork was published in bulletins for the "Tokyo Majin Gakuen" FC.

Kawanabe is also a screen and stage actor. He's performed in various theatre productions, and has appeared in several TV commercials. He was in the TV drama "Sayonara, Ozu-sensei", and was cast in the live-action movie for "GTO" (as Saitou).