Ken Sato. is a star player in American baseball and is the human host of Ultraman. His real name is Kenji Sato. He spent his childhood in an apartment building in Odaiba, where, influenced by his parents, he developed a strong interest in baseball from a young age and harbored great admiration and longing for the figure of Ultraman. Kenji's father, Hayao, hoped that his son would become the next Ultraman, following in his heroic footsteps. However, his mother, Emiko, insisted that Kenji become an outstanding baseball player. One night, Gigantron's attack ultimately changed the fate of this family. Due to the frequent Kaiju attacks in Japan, Kenji's parents decided to separate. Kenji moved to Los Angeles, United States, with his mother, while his father, Hayao, stayed in Tokyo. This upheaval left young Kenji feeling confused and pained, unable to comprehend the reasons behind his parents' separation. He began to believe that his father had abandoned him and his mother to pursue a career as a kaiju researcher and as Ultraman. This belief left a deep mark on his adult psyche, causing him to grow weary of the prospect of becoming Ultraman and instead focus on his baseball career, all while becoming distant from his father. Despite everything, Kenji still inherited his father's Ultraman abilities. Ken chose to stay away from the media spotlight, avoiding multiple interviews and keeping a certain distance from his teammates. The deep pain and misunderstanding regarding his father, along with the difficulties he faced in adjusting to the new environment after moving to the United States, made it hard for him to fully open up. Despite the increasing attention from the public, Ken insisted on maintaining his unique style, wrapping himself in a persona of pride while silently enduring his inner struggles. A few months later, when Hayao was injured and hoped his son would take on the responsibility of Ultraman. Kenji decided to move back to Japan and in the mix his mother had disappeared.