Koji Doigaki

is one of the main characters of Ultraman Cosmos. He is a member of Team EYES. With vigor and a naive personality, Doigaki calls himself a genius scientist who can dabble in biology, physics, pseudoscience, and more for analysis. Contrary to the first impression of a burly stature, he has a delicate heart. He is often at the base responsible for developing equipment, including TECCH Spinnar, and performing analysis, including relics. Behind-the-scenes work on strategic planning and more. Initially, he wasn't good at driving the TECCH Thunder 3 and couldn't master it very well, but he managed to get over it.
==History==
===Ultraman Cosmos===
Doigaki is a member of EYES and an analyst on the team. He was the junior of captain Harumitsu Hiura when he was at the MITI Institute, and he is closely watched by the SRC. He joined EYES after graduating from college.
Doigaki's parents were Katsushika fishermen from Tosa, Kochi Prefecture. Since he did not want to inherit the family business, his relationship with his father was not very good. 
He secretly fell in love with Yukari Yoshii, a junior in college. As Yukari was involved in monster attacks many times, Doigaki's behavior of protecting Yukari many times made their relationship more and more favorable, and the two eventually fell in love. 
In the final stage of the story, he learned from Fubuki that Musashi was Cosmos's identity. 
After Cosmos and Musashi purify Chaos Header in the final chapter of the series, Doigaki, along with the other EYES members, watches Cosmos leave Earth. 
===Ultraman Cosmos 2: The Blue Planet===
Two years later, Doigaki participated in the battle against Sandros with the other members of EYES. He witnessed the return of Cosmos.
===Ultraman Cosmos vs. Ultraman Justice: The Final Battle===
After three years, Hiura retired from EYES and assumed the chief role in the Science Section of SRC.
When Musashi disappears, he reunites with other former EYES members, and they travel to the forest where Musashi first met Cosmos in search of the missing Musashi.
Later with the assistance of Jin and Shau, Doigaki and Musashi's friends combine their energies to try to resurrect Cosmos, and in the end, witness the emergence of Ultraman Legend. 
==Merchandise==
*Ultraman Cosmos Deformed Pattern Acrylic Charm (2020)
**Release Date(s): October 29, 2020 (Bandai Fashion Webstore), August 2021 (Premium Bandai)
**Price: 550 yen for each piece
**Materials: Acrylic, metal (chain)
:Released as part of the Cosmos-themed Deformed Pattern Acrylic Charm series to commemorate the show's 20th anniversary, Doigaki (which is drawn in an Anime-fied style) is one of the items to be produced as hanging acrylic keychain.
:He (and the rest of the characters) is available as a made-for-order item (where the customers can choose one during purchase) for Bandai Fashion's website in 2020, and later the Premium Bandai site in August 2021.
==Gallery==
===Ultraman Cosmos===
Koji Doigaki 1.png
Koji Doigaki TV1.png
Koji Doigaki TV2.png
Koji Doigaki TV3.png
Koji Doigaki 4.png
Koji Doigaki TV9.png
Koji Doigaki TV4.png
Koji Doigaki 3.png
Koji Doigaki TV5.png
Koji Doigaki TV6.png
Koji Doigaki TV7.png
Doigaki kouji.jpg
Koji_Doigaki_TV10.png
Koji_Doigaki 2.png|Koji and Yukari
Yukari_Yoshii_8.png
Yukari_Yoshii_6.png
Koji_Doigaki_TV8.png
===Ultraman Cosmos 2: The Blue Planet===
Koji_Doigaki 6.png
Ayano_Morimoto movie 4.jpg
===Ultraman Cosmos vs. Ultraman Justice: The Final Battle===
Harumitsu_Hiura_movie_3_1.png
Koji_Doigaki 7.png|Koji and Mienin
Shinobu_Mizuki_Movie_3_2-.png
Category:Allies
Category:Ultraman Cosmos Characters
Category:Ultraman Cosmos
Category:Male Characters
Category:Human Characters
Category:Scientists
Category:EYES
Category:EYES Members