Ryūya

Visual Novel
At the beginning of the second chapter of Air (Summer), Ryuya was assigned to guard Kannabi-no-Mikoto at a Shrine dedicated to housing "winged ones." There, Ryuya met Uraha (Kanna's personal caretaker).

Ryuya was abandoned by his parents at a young age and left for dead until being found by a traveling monk. After traveling with the monk for a period of time, they were confronted by bandits who sought to rob them. When the monk couldn't produce anything of value, the bandits killed him as Ryuya watched. He was spared by the bandits, since he was so young, but the event impacted him and his outlook on life.

On his own again, Ryuya stole a sword and became a mercenary. Since he began using a sword from a young age, he became a very skilled warrior (as demonstrated by his ability to subdue skilled warriors without using lethal force, even when outnumbered). At some point, he was enlisted by the imperial army to serve as a personal bodyguard for VIP's, which eventually led to the start of his contract to guard Kanna.

Ryuya was in charge of the security detail at Kanna's shrine. He has many interactions with Kanna and Uraha, and eventually learns of Kanna's orphan status and her desire to see her mother. Ryuya quickly learns that the guards under his command are fresh recruits, and his military saavy warns him that something is amiss when his superior demands him to gather all documents surrounding the shrine in preparation of Kanna's moving to a new shrine.

Not wanting to part ways with Kanna, he conspires with Kanna and Uraha to escape the shrine the night before her scheduled departure, ostensibly to take Kanna to meet her mother. As Ryuya suspected, an army of mercenaries marched to the shrine, killed the poorly trained guards and caretakers, and burned the shrine to the ground. It is implied that all of Kanna's previous homes suffered the same fate, unbeknownst to Kanna. It is later revealed that the mercenaries were attempting a coup of the established government, and part of this entailed eliminating the winged ones, as they were kept as instruments of war and objects of worship by the then-emperor. After almost killing one of the mercenaries, Kanna forces Ryuya to promise never to kill a man while in her service.

Ryuya continued to guard Kanna and Uraha as fugitives, evading search parties and checkpoints set up by the imperial army. Kanna very seriously hints that she has a romantic interest with Ryuya, only to be interrupted each time. Ryuya and Uraha used rumors and documents from the shrine to eventually located a Buddhist shrine (the other was Shinto) which contained Kanna's mother. Monks guarded the shrine, who would not allow them to enter. Ryuya struck them all down, but was wounded in the back by a monk who's life he spared. While leaving the shrine together with Kanna's mother, they were ambushed by mercenaries and Kanna's mother was mortally wounded. Before she died, she slew many of the mercenaries with a magical gust from her wings and spent time talking with Kanna. During this time, the imperial army also approaches and surrounds the group. Kanna flies into the sky and distracts the imperial army and Buddhist monks while Ryuya and Uraha escape the shrine, however Kanna is banished by a Buddhist curse in the process. Ryuya's back injury begins to intensify from this point forward as a result of a different curse that was transmitted to Kanna from her mother after death.

Ryuya and Uraha then travel together and live together in search of knowledge of what happened to Kanna, until ending up at an old temple. Uraha and Ryuya studied together with the wise monks from the temple. They discover that Kanna was banished to a realm where she dreams about Ryuya not escaping and instead being killed by the imperial army, and her soul is residing in the sky. After learning that the curse can not possibly lifted for at least 100 years, Uraha suggests leaving behind a child to start a multi-generational journey to save Kanna once it is possible to lift the curse. This, combined with Uraha's development of Houjutsu powers, heavily implies that Yukito Kunisaki is the final result of this effort. Uraha and Ryuya conceive a child, but Ryuya's weakness due to the Buddhist curse develops into a mortal illness, and he dies before the child is born. In his final moments, he comes to understand that spending time by Uraha's side and trying to save Kanna had allowed him to live a happy life. He is last seen venturing into the sky in a dream-like sequence to meet with Kanna.

Anime
Ryuya is a samurai assigned to guard Kannabi-no-Mikoto and soon accompanied her to the shrine where Yao Bikuni (Kanna's mother) was imprisoned. After Yao died, he accompanied Kanna back to the shrine where she lives only to find it invaded. There were monks who tried to put a curse on her and she decided to fly to escape the curse but before she could fly out of reach, she was hit by the invaders' arrows and then injured, she was caught by the curse and disappeared. After seeing the situation, Ryuuya was enraged and tried to kill the invaders who shot Kanna, but he was stopped by Uraha.

Ryuuya dedicated the remainder of his life to finding a way to lift the curse placed on Kanna. Later on, they came into the temple of monks who care for the winged race. They said that Kanna was the last of the winged race. Uraha who was taught of sorcery by the monks, told him that the only way to save Kanna from her nightmares is to make an offspring. He died young because his wound slashed by a sword didn't heal because he had touched Kanna's mother who was tainted by a curse.

In Air: The Movie, Ryuuya is shown to actually be Kanna's lover and he has no apparent romantic relationship with Uraha. He appears physically different from his game counterpart, with darker hair and a generally more reserved personality; changes similar to Yukito Kunisaki's own movie counterpart. After learning of the punishment imposed on Kanna for falling in love with him, he helps her escape captivity, though he dies from a spear wound from behind soon after she takes flight. He appears to be the source of Yukito's puppet controlling powers in the film (he is able to mix his powers with his actual swordplay as he controlled tops to dance on his sword blade during the battle to help Kanna escape) while Uraha was the source in the game.