In ULTRAMAN, Sara presented herself as a professional and cold to the point of apathetic and completely detached from others. However, Maki soon noticed that this cold demeanor of hers was a mere facade, as she revealed to be considerate enough to allow him to reunite with his family. It is then she finally opens to the Next's host about her history with Udo who has been assimilated by the One, and later entrusted Udo to put her fiancee to rest.
Sara was first seen in a lab preparing a weapon the kill the Beast the One. As The One was escaping the facility, she shot the monster. After the beast reveals Udo's face, Sara was shocked, allowing the beast to escape. Blaming herself for this she would later appear excessively professional refusing to let her feelings cloud her judgement again. Sara acted as a spy on Maki when he was with his family after watching Maki's debriefing and his testimony about his experience and crash involving the red light. Sara then declares him a monster despite him showing no signs of transformation. Soon, she posed as tourist on Maki's plane taking gun point Maki to the Japan Air Defense Force where she explained the situation. She had Maki used as bait in a derelict facility wherein they had hope The One would be drawn towards him so the military could shoot the beast with their special poison darts that Sara had used before.
However, the space beast had developed an immunity to the poison and the soldiers there were slaughtered when it mutated into its next form. Sara was almost killed when Maki escaped and then transformed. To her surprise it was not a monstrous form like Udo's but a silver giant. She and the rest of surviving soldiers watched as the silver giant, Ultraman the Next, fights the space beast, but when the creature threatened Sara’s life, Next dove in front of the tail, taking several whips before forcing the creature into retreat where it broke through the wall and vanished into the wilderness.
After the battle, Sara confronts Maki who called her out for her callous use of him as bait. Sara refused to admit any wrongdoing, saying that Udo (the One's host) predicted another person would suffer a similar fate to him and that the two would be enemies. When asked about her intentions Sara stated that she would not kill Maki, unlike Udo he did not become a monster and was in control of himself, saving her from the One's attack to her surprise. She stated that 'the Next' was for the moment not their enemy. Maki refused to help, refusing to be a 'useful monster'.
When Maki escaped the escort due to vision of his son being brought to hospital, Sara immediately give chase, but allowed him to reunite with his family rather than forcefully taking him away. Returning to the escort, Sara and Maki bonds as the latter revealed to seeing that her callous demeanor was the mere act, in which she revealed that Beast The One has assimilated his fiancee, Udo, and she blamed herself for allowing it to escape.
She appeared in episode 33, were she visited the TLT Japan base to talk about the TLT North America's decisions regarding Lethe. She explained the origins of Lethe and the Visitors to the Night Raiders and the truth regarding erasing the world's memories of The One and Ultraman.
At the end of episode 34, she departed the base stating that people's feelings were entrusted to Maki as he saved the world and stated that people's feelings were entrusted to the current Deunamist, Ren Senjyu.