Ryou Tenkasei, RyuuRanger
Full Name: Ryou Tenkasei of the Heavenly Fire Star
Ranger Designation: RyuuRanger
Weapons: Dai Buster, Dai Rod with Halberd, Double Dragon Swords, Dairinken
Gear: Aura Changer, Lai-Lai Jewel, Red Kiber 1
Special Attacks: Chi-Power Bomber, Inazuma Enjo Ha, Ryusei Senko
Mythical Chi Beast: Ryuuseioh

Ryou Tenkasei was twenty-three years old when he became a Dairanger. In his daily life he was an apprentice-cook at a Chinese restaurant Yokohama Chinatown at Yokohama. And his dream was to be the number-one Gyoza cook in all of Japan. He was a descendant of the Dai tribe. Ryo had an eighteen year old sister, Youko, who apparently was born around the same time their father supposedly died. In the first episode, Ryo was innocently taking out the garbage at work one day when a crazy tentacle (Baron String) took off with one of his friends and he pursued it, until it attacked him. In the end he was rescued by a fire-breathing dragon (Ryuuseioh), which chose him as the Ryuuranger, wanted to take him home and keep him as its pilot. Until episodes 7 and 8, he finally found out his father wasn't really dead but Chouryou who was the original Ryuuranger and betrayed his people to become servant of Gorma High Priest Saw. Chouryou captured Lin, Kazu and Daigo along with the High Priest Saw, leaving only a frightened Shouji to relay the message to Kaku. Kaku locked Ryou in a closet and had Shouji as guard. Ryou tricked Shouji into opening the door and went after Chouryou. He was captured by him and almost killed until Kaku revealed Ryou was his son. Ryou couldn't understand how this traitor slaughtered his own team member and was his supposedly dead father. Although Ryou implored to know how the man who loved his mother could possibly be the same person, Chouryou made no attempt to explain himself and left him a photo of the loving family. Chouryou attempted to kill High Priest Saw but was killed himself.

In Episode 15 Youko was kidnapped and Ryo had to face the Three Stupid Gohma on his own, Until his friends caught up with him. In Episode 21 and 22, he was the kidnap victim, and very nearly ended up dead as a Gohma sacrifice. And then in episode 26, he met someone who was Jin, a gentleman assassin who had a penchant to kill martial art masters. He was a mix between everything Ryo wanted to be, and everything that he feared. hough Master Kaku warned Ryou to stay away from Jin, who had no access to Ki-power, because he believed Ryou would be defeated if he challenged such a master. Even with this warning, Ryou became fixated on Jin. In another dual in Ryou called out his Ki power in frustration of defeat and blasted Jin. This enraged Jin, and he beat Ryou into the ground, leaving him bleeding in the grass. But Ryou needed to learn the skills Jin had developed, to save his friends who had been captured by a deadly Gorma. He also felt as he needed to prove himself capable of defeating this man who used those extraordinary talents to murder. And so after forcing himself to a speed and strength he never before had, he faced Jin a third time. Jin warned Ryou that he would kill him this time, even though he felt pity and considerable respect for him. Ryou was wearing springs, and now he broke them off. And with the springs gone, he was blindingly fast. With the battle won, Ryou took off to fight the Gorma monster and save his friends. Jin, on the other hand, washed off on the beach and Zaidosu, who witnessed the battle, gave him power to become the Demon Boxer. Jin's punch injected a special kind of curse-poison and was injected into Ryou. He nearly killed Ryou but Ryou defeated his fears, and the two men confronted each other again.Zaidosu who was watching the fight, told the Cannon-Gorma to kill the winner of the battle. And though the battle was not quite over, it looked like that would be Ryou and the Cannon fired. But Jin heard the shot coming and leaped between to protect his enemy. The shot took him down, and Ryou was stunned. Jin had only saved Ryou because he wanted to defeat him in fair combat. Jin wanted to be the only one to do in him.

Ryou later found Jin unconscious and took care of him. Ryou had begun to realize what Jin should have been, and thought something must have happened to warp him into what he had become. And he was determined to unwarp Jin. At night while Jin slept, he tranformed into a blood-drinking monster Garouki which went out and killed people. One morning, Jin awoke to find some strange growth on his right arm. Ryou took Jin out into the daylight in a wheelchair and Jin asked him why he was being so kind. Ryou fumbled with the explanation, but could only come out with the truth. That he could not bear to see him die that way. Jin was an extraordinary warrior, with honor and courage enough to break a heart. And that at last Jin understood. Jin made Ryou promise, if he became a monster, to please be the one who defeated him. Ryou was frightened and confused, but Jin told him where to strike, and made him promise. For shortly after that Jin did become the monster Garouki, under Zaidosu's control.It broke Ryo's heart to fight him, knowing Jin was not responsible for what was happening and would never have chosen it. Ryou reluctantly struck at that weak point, and broke Jin free from Zaidosu's control. They fought side by side until Zaidosu regained control and turned Jin back into the Garouki, but the Dairanger used their cannon to break the power again, leaving only Jin. And Jin, though bleeding and weakened by the battle, challenged Ryou. While the others watched, the two men squared off a final time who perhaps weren't fighting wholeheartedly. Still, it was Ryou who broke through Jin's guard to punch him, but stopped a short distance from Jins face. Jin knew because Ryou particularly would never be able to strike the final blow, that there was no way the pair of them could ever test each other fully. Ryou tried desperately to do something in return for all that Jin had inadvertently given him. He did everything in his power to save the other man's soul. Ryou would rather he had stayed, but Jin could not and left. Jin's spirit later appeared to Ryou to beat sense into him to defeat the Gorma. Years after they won the war, he saw his nerdy-like grandson fight a New Gorma in Dairenou.

Ryou deeply trusts his teammates. Ryou specializes in Red Dragon Fist. Ryuu Ranger can translate to Dragon Ranger. His other attacks are the 'Inazuma Enjo Ha' which is in some sources translates to Lightning Blaze Destruction and in some others, Heaven Fire Star Lightning Flames Destruction. This is a straight fire attack. 'Ryusei Senko' is translated in some sources as Meteor Flash and in others as Shooting Star Lightning Flash.