Kenji “Ken” Sato

He is a star player in American baseball and is the human host of Ultraman. Ken Sato was designed as an ambitious, self-assured Japanese-American who inherited the secret ability to transform into Ultraman. He fights monsters while grappling with deep-seated estrangement from his father, from whom he was separated as a child. Ken soon faces an unexpected "parenting" situation when he is forced to raise the offspring of his greatest foe, a newborn Kaiju.

Struggling to balance the roles of a teammate and a new father, Ken must confront his own ego, reconcile with his estranged father, and navigate the challenges posed by the conniving Kaiju Defense Force. Through these trials, Ken discovers what it truly means to be Ultraman. Kenji Sato is the son of Hayao Sato and Emiko Sato, born in Tokyo, Japan. 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.

Twenty years later, Kenji finally realized his dream of becoming a baseball player. As the star player for the Los Angeles Dodgers in Major League Baseball, he was active in the baseball world under the name "Ken Sato." With his outstanding performance, he earned numerous honors, including the Gold Glove Award and the Silver Slugger Award. Throughout his baseball career, Ken achieved remarkable results, boasting a batting average of 420 and 624 successful stolen bases. However, he never managed to win a championship.

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. could no longer fulfill his duties as Ultraman, he contacted Ken and Emiko, hoping that Ken could take on his identity to protect Japan. This meant that Ken would have to assume the role of Ultraman, destined to shoulder the responsibility of saving the world. Emiko endorsed this plan and wished for Ken to adjust well to his new life in Tokyo. However, one day, Emiko went missing in an accident and was not heard from for a long time, plunging Ken into immense grief. He sought help from Mina, asking him to track his mother’s last known GPS location, but to no avail. His mother’s disappearance became an unhealed wound in his heart.

Amid complex emotions, Ken reluctantly abandoned his life in the United States and returned to Japan. He took up residence in a base near Tokyo Bay named "Ultra Base" and, under the guise of playing for the team, joined the Yomiuri Giants. This sudden move garnered significant attention from major sports media outlets in Japan. At the press conference, Ken displayed an extremely arrogant and boastful attitude, constantly bragging about his athletic abilities and promising to lead the struggling Yomiuri Giants back to the top. Nevertheless, a sports journalist named Ami Wakita noticed his actions. When Ami inquired if Ken had come back to Japan because of the "emotional strain of losing a family member," Ken avoided the question and promptly departed.

Following his inheritance of his father's powers, Ken became the new Ultraman and began to fight Kaiju attacks in his role as the current Ultraman. However, initially as a novice, he lacked the determination, maturity, and sense of responsibility needed to effectively repel the Kaiju. Consequently, he frequently faced counterattacks from the Kaiju during several battles and was even disregarded by the quasi-military organization KDF, whose primary goal was to eradicate Kaiju threats.

After the battle with Neronga concluded, Ken went to meet journalist Ami for an interview as scheduled. They had a deep conversation at a soba shop, during which Ami's questions gradually caused Kenji to start questioning his own choices. He realized he hadn't been aware of the harm caused to the surrounding environment and innocent civilians during his battles. Moreover, Japanese people traditionally expect Ultraman to engage Kaiju with minimal collateral damage, a concept Ken struggled to grasp. He remained more interested in his baseball career and viewed "becoming Ultraman" as an unnecessary source of pressure that he wanted to avoid. During the baseball competition, Ken's American-style attitude and demeanor clashed with the atmosphere of Japanese baseball. Furthermore, his aloofness from other team members and his abilities made him a target for taunting by opposing players.

He has a giant pink Baby Kaiju, named Emi.