|Transformation Item||Ultra Badge|
|Home world:||Earth (Showa Universe)|
|First Appearance:||Ultraman Taro Episode 1: "Like the Sun, Mother of Ultra"|
|Last Appearances||Ultraman Taro Episode 53: "Farewell Taro! The Ultra Mother!"|
|Family||Unnamed mother (decreased)|
|Portrayed by||Saburo Shinoda|
Kotaro Higashi wanted to be a championship boxer. However, destiny had other plans as he fell thousands of feet from the Earth after Astromons shook him off throwing him to the ground. The Five Ultra Brothers brought Kotaro's body to their homeworld of Nebula M78 many years into the past. It was there that Mother of Ultra merged Kotaro with her son Ultraman Taro, who would join the Ultra Brothers. After the merge was complete, Kotaro was taken back to present day Earth and as Astromons was ravaging a city Kotaro turned into Ultraman Taro. Not long after Astromons's defeat Kotaro joined ZAT and fought in a new era of kaiju and alien invasions.
In the final episode, Kotaro gave the Ultra Badge back to the Lady In Green, separating from Ultraman Taro. However, not long after he separated from Taro, Alien Valkie attacked Tokyo by surprise to get his revenge on Ultraman Taro, without knowing Kotaro had been separated from him. Kotaro fought him with his own human abilities and managed to defeat him by blowing up a nearby gas tank. After that he left ZAT to pursue his dream of becoming a professional boxer. He was never seen again afterward. His current location is also unknown.
The Ultra Badge was presented to Kotaro Higashi by Mother of Ultra, Kotaro takes the Ultra Badge from his shoulder and holds it up above his body before shouting "Taro!" signaling Taro to appear. At the series's end, the Ultra Badge was ultimately returned back to Mother of Ultra at Kotaro's request to not need to rely on Taro's power.
- Kotaro Higashi is the first male Human Host to separate from his Ultra willingly. He also was one of the few Ultra human hosts to sever his relation with an Ultra Warrior.
- Kotaro was the first and only Ultra human host/form had fought his last battle by himself without any help nor transforms to Ultraman. Kotaro was also the first Ultra's human hosts/forms to have only appeared in one series (Ultraman Taro) and he was never seen again afterward.
- Ultraman Taro's human host, Kotaro Higashi was meant to return in Ultraman Mebius to assist Mebius like other Ultra Brothers's human forms/forms, but he couldn't make it because Saburo Shinoda, his actor was attending someone's funeral at the time. Saburo Shinoda was also supposed to voice for Taro but this decision was also scrapped due to the funeral he was attending. Susumu Kurobe and Kohji Moritsugu admitted that Saburo's inability to return was a huge regret.
- Saburo Shinoda, Kotaro Higashi's actor, was also the first voice actor for Ultraman Taro (but he only voiced for Taro in the Ultraman Taro series only). Despite that, his grunts still kept and reused for Taro's many later appearances
- During the time of Ultraman Taro, Saburo Shinoda states that even himself was shocked upon learning of Kotaro's decision to leave his Ultraman and continue his life as a normal human. Unfortunately, this was the writer's decision.
- Before casting as Kotari Higashi in Ultraman Taro, his actor Saburo Shinoda has made an appearance in Ultraman Ace episode 20 as a minor character named Ichiro Shinoda.
- Kotaro Higashi has been mentioned in Shin Ultraman Retsuden episode 8 by an Alien Valky of that series, who also claimed himself to be the same individual that Kotaro attacked.
- This is also the only time Kotaro has been mentioned after the end of Ultraman Taro.