Takeshi Yoshioka (吉岡 毅志 Yoshioka Takeshi) is the actor of Gamu Takayama in Tsutomu Shinsei's own world. 20 years later in Tiga, Dyna, and Ultraman Gaia Novel: The Adventure in Hyperspace, he was given the Esplender from his own character, allowing him to transform into his series' namesake Ultraman in the wake of Kaiser Gyrares XIII's attack.
Ultraman Tiga, Ultraman Dyna, & Ultraman Gaia: The Decisive Battle in Hyperspace
Takeshi Yoshioka's sole appearance was within Tsutomu's own cassette tape of an Ultraman Gaia episode, wherein he portrays his character Gamu and Satanbizor's own disguise. Through the Red Sphere's help, Tsutomu would bring the actual Gamu to his world, thus creating a series of events which lead to the movie's plot.
Tiga, Dyna, and Ultraman Gaia Novel: The Adventure in Hyperspace
20 years after King of Mons' destruction, the 29-year old Tsutomu came across Takeshi playing the role of a kidnapper in an unnamed film. While Takeshi took a rest in a cafeteria, Tsutomu greeted him where the actor expressed his regret of playing Gamu, due to how it negatively affecting his career later on while crushing Tsutomu's spirit as an Ultraman fan by telling to give up. Despite this, Takeshi does not find Tsutomu's claim of meeting the actual Gamu Takayama as a lie.
"I was entrusted with this power. To protect this world, to fulfill my promise with Tsutomu. Gaia!"
- ―Takeshi transforming into Ultraman Gaia.
When the mad artist Shunsuke Kuji summoned Kaiser Gyrares to life and wreaking havoc, Gamu was summoned by Yu Hirama's colleague where he apologized to Tsutomu for their previous encounter. His attempt to save a little girl earned him the recognition from the actual Ultraman Gaia, resulting in him grabbing an Esplender toy and used it to transform into the very Ultra itself. Although an actor, Takeshi's mind resonated with the actual Gamu from another world, first using V1 and later on evolves into V2 to destroy Kaiser Gyrares XIII. As Gyrares fused with other breeds of monsters from various Ultraman Series into Demon Gyrares XIV, Gaia received help from Tiga, Dyna, GUTS and Super GUTS to destroy the monster, thus saving the world.
- Takeshi's transformation into Gaia V1 despite the Ultra has already evolved into V2 may be contributed to the fact that he has little to no combat experience, hence Gaia's constant evolution in the fight to demonstrate his growth of power. This is also demonstrated when Takeshi, as Gaia V2, managed to deal the finishing blow on Gyrares, the same monster that recently killed King of Mons.
- According to the back note of the novel, Takeshi's portrayal in the novel is a close interpretation to his real life actor.