Kenjirō Ōta serves as an officer in the navigation division aboard the space battleship Yamato, holding the position of chief weather officer with the rank of ensign. His duties involve observing and reporting vital space weather conditions and trajectory information for the ship's navigation. Originally from Osaka, he possesses a bright and optimistic personality, acting as a mood-maker among the crew and boosting morale through his demeanor.

Ōta exhibits a notable inclination toward lighthearted behavior and pranks. During celebrations for the Yamato's transit of the solar system's heliopause, he tricked nurse Makoto Harada into wearing a skimpy maid costume under false pretenses, resulting in her public embarrassment. Upon discovering the deception, Harada retaliated by forcing Ōta to consume alcohol far beyond his limits. In another instance, he took advantage of Yasuo Nanbu's unconscious, drunken state to play a prank on him. These actions highlight his role as the crew's jester.

His active participation in the farewell celebrations before the ship's departure from the solar system further cements his integration into the Yamato's social fabric, reflecting acceptance by fellow crew members despite his mischievous tendencies.