Ryu Aihara

Ryu Aihara (アイハラ・リュウ, Aihara Ryū) is the only surviving member from the original GUYS. He was very close to Kazuya Serizawa.

Ultraman Mebius
When a monster first appeared, GUYS Japan was sent to take care of the monster. This was the first monster attack in nearly 25 years and no one was prepared for what would come in the battle. Dinozaur easily defeated his comrades, and the remainder was only the fighter plane of him and Serizawa. Serizawa, not wanting Ryu to die, ejected his seat. He is a good man, but has a cold exterior after what has happened to his friends. When Mirai first meets him, he is reciting the Ultra Five Oaths and Mirai joins in as well. Later on during Mebius' first battle, he berates Mebius for failing to defend the city and shielding himself with buildings, then he berates himself for failing to protect his friends. He feels responsible for all the new members of GUYS and tries his best to protect them. He habitually recites the Ultra Five Oaths after learning them from his previous captain. He was told the history of the country of light by Mirai in episode 30. During Serizawa's final battle as Hikari, Ryu rushes into the battle in a fit of rage at the sight of his former captain being killed. Ryu himself is seemingly killed until it is revealed that Serizawa passed on the Knight Brace to him, allowing him to become Hikari's temporary host. Mirai Hibino/Ultraman Mebius was able to contact him alone in episode 50. Ryu became the new captain of CREW GUYS after episode 50. 20 years old.