Koh, Melto, and Asuna are three members of the Ryusoul Tribe who have just inherited the mantle of the Ryusoulgers and the duty of protecting Earth from their masters. The three of them soon meet a vlogger named Ui Tatsui, who is searching for proof of the tribe's existence for her father. The group's challenge begins when the Ryusoul Tribe's sworn enemy, the Druidon Tribe, return from their long self-imposed exile in space and send a giant monster known as a Minosaur to destroy the temple holding the resting Kishiryu.
The three Ryusolgers look for their Kishiryu after they disappeared following their first battle with the Druidon, with some help from Ui and her father, Naohisa Tatsui. They encounter a fencer named Mishima, who they learn is the host of an immature Unicorn Minosaur, who is siphoning the fencer's life force to reach his full size.
Koh and his friends meet the other Ryusoulgers, brothers Towa and Bamba, while pursuing the Medusa Minosaur. The brothers are unimpressed with the new Ryusoulgers and refuse to accept them as allies. To make matters worse, Ui is revealed to be the Minosaur's host and Bamba attempts to kill her.
Towa and Bamba begin searching for their Kishiryu before learning Koh has a map to the temples holding them, with the former challenging him to a duel over it. The ensuing rivalry soon becomes detrimental when the Kraken Minosaur starts putting people to sleep.
As Towa begins to grow close to the staff of a local animal health center, he joins Koh when the latter confronts Tankjoh in an attempt to avenge Master Red. However, the two of them fall into a trap set up by the Druidon and the poisonous Cerberus Minosaur.
With Tankjoh going on the offensive after harnessing seismic energy, the Ryusoulgers fall victim to the infectious properties of the Cerberus Minosaur's poison. After Asuna and Bamba are infected, Koh and Melto attempt to find a cure so they can stop Tankjoh's rampage together.
Princess Cardena of the Planet Cepeus arrives on Earth to request the Ryusoulgers' help in finding her missing sister, who she claims was taken by the Druidon. Soon after, the Ryusoulgers confront the Druidon sorcerer Wiserue.
The Ryusoulgers rescue the alien princesses, who wish to give Tyramigo an energy source that will increase his power tremendously in return. Though Koh immediately trusts them, Melto and Bamba become suspicious of their intentions.
The Ryusoulgers find a game that leads participants to a magical wonderland where anything they wish for comes true. However, Melto is not convinced and suspects the Druidon are behind this so-called game.
Just as the Ryusoulgers go up against an invincible Minosaur capable of reflecting attacks directed against it, its host unexpectedly saves Asuna. While Koh tries to attack their latest foe directly, Asuna tries to save the monster's host even as Wiserue attempts to complicate matters for her.
The Ryusoulgers and the Druidon are on the hunt for the Kishiryu DimeVolcano, who the Ryusoul Tribe sealed away due to its destructive power. However, to acquire the Kishiryu's loyalty, both parties must answer DimeVolcano's riddles to prevent it from going on a rampage.
The Ryusoulgers attempt to recover DimeVolcano after letting it get away, but Wiserue refuses to give up his quest to control it and has a Minosaur with apparent fire resistance created to lure the Kishiryu out. Just then, the mysterious Gaisoulg makes himself known to the Ryusoulgers and the Druidon in order to fight them both.
Japan's first female prime minister, Mioko Karino, a woman of mystery, appears to know Bamba and offers to tell him and Towa about their Masters on the condition that they destroy the Minosaur born from her body once it has fully matured.
As the Ryusoulgers gain a reluctant ally from the Sea Ryusoul Tribe named Canalo, who would rather find himself a bride, they all find themselves facing a bloodthirsty Druidon general who seeks their people's total annihilation.
Canalo refuses to join the Ryusoulgers whilst attempting to get his little sister Oto back to the sea after she followed him ashore. Amidst a Minosaur attack, Oto is taken hostage by the Druidon in order to force Canalo to fight the Ryusoulgers.
Canalo begins to see the Ryusoulgers in a better light after Koh saved Oto, but his Kishiryu MosaRex refuses to involve himself with the main Ryusoul Tribe for reasons unknown. As Canalo tries to convince his Kishiryu, he and the Ryusoulgers find themselves facing Gachireus after he upgraded himself using combat data he collected from their previous battles.
With Gachireus gone, Wiserue returns and uses a Minosaur to capture MosaRex so he can use his magic to turn the Kishiryu on Canalo. In response, he goes to the Ryusoulgers and MosaRex's brother, DimeVolcano, for help.
While fighting the Druidons' latest Minosaur, the Ryusoulgers' suddenly lose their ability to transform. To make matters worse, Bamba and Canalo come to blows over the Minosaur's host, causing the monster to grow faster and bigger than past Minosaurs.
When elementary school students that the Kishiryu Tyramigo befriended during his walk and most of the Ryusoulgers disappear as part of a Druidon plot, the Kishiryu and Melto must find a way to rescue their friends.
The Druidon's latest Minosaur appears to be a failure, but under Wiserue's wing, it becomes a deadly threat as it causes the Ryusoulgers to disappear one by one. With Towa the last one standing, Gaisoulg returns to challenge him.
While Canalo and MosaRex head off to investigate a mysterious power source coming from outer space, the other Ryusoulgers try to uncover the mystery behind the disappearances of several animals and plants along with the mysterious resurrections of several dead people: including Ui's mother, Master Pink, and Tankjoh.
In a shocking turn of events, the Ryusoulgers discover a Minosaur born from Master Pink is responsible for the resurrections. Armed with this knowledge, Koh leaves to face the Minosaur while the other Ryusoulgers confront the revived Tankjoh.
With their Ryusouls mysteriously losing power, the Ryusoulgers attempt a Ryusoul Trade to stop this from happening. To assist them, Canalo provides a Ryusoul capable of granting wishes, but Wiserue gets involved so he can take it for himself.
Canalo rescues and falls in love with the daughter of a dojo master, so he takes up karate to impress her and earn her father's respect. From the sidelines, Oto secretly asks Melto to help ensure her brother's success.
The creator of the Druidon's Minosaurs, Kleon, puts out a viral video starring himself and the Druidon's foot soldiers dancing like crazy, as well as a hidden Minosaur capable of stealing the souls of anyone who watches the video. When Ui, Oto, and Tyramigo fall victim to the plot, the Ryusoulgers will have to enter cyberspace in order to save them.
Seemingly out of nowhere, another member of the Ryusoul Tribe and Koh's fellow student, Nada, appears before the Ryusoulgers and asks to join them in their fight against the Druidon. When Koh is taken down by their enemies' latest Minosaur, he suddenly feels he is not worthy to be a Ryusoulger and considers passing the title of Ryusoul Red to Nada.
Nada leads the Ryusoulgers to the resting place of the kangaroo-like Kishiryu, Pachygaroo, and encounter its child, Chibigaroo. While they attempt to break the Kishiryu's seal, an apparently resurrected Gachireus suddenly appears and buries them alive.
Kleon manages to sneak a microscopic Minosaur into Asuna's body, forcing Koh to shrink down in order to save her. However, his efforts are complicated when he finds that the monster's tail is tied around Asuna's heart, meaning he is unable to kill it without killing her at the same time.
Canalo meets a woman named Yui and chooses to marry her on the spot, causing the other Ryusoulgers to believe he is leaving them just as they are forced to contend with a Minosaur throwing poisonous garbage all over the city.
Towa and Bamba learn that Nada is Gaisoulg, but Koh refuses to believe his friend has succumbed to evil and tries to get close to him. Just then, Wiserue sends a high spec Minosaur to attack the Ryusoulgers, but Gaisoulg joins the fray to seemingly aid the latter against it.
After a flying Minosaur entrances everyone in the city, including most of the Ryusoulgers, the unaffected Canalo and Oto as well as an injured Koh have to locate a sky Kishiryu in order to combat their airborne foe all while Nada and the Druidon continue to hinder their efforts.
Even in spite of all that Nada has done, Koh firmly considers him a Ryusoulger and fights to save him from the Gaisoulg armor just as it starts to take over his body. Meanwhile, Gachireus goes on the attack alongside a Minosaur capable of spreading a rainbow-colored rain that causes people to go mad with anger and attack each other.
Just as Koh helped free Nada from the Gaisoulg armor, a Druidon assassin called Uden attacks the Ryusoulgers one by one; using his powers to absorb them and steal their attacks. Vowing to make amends for what he did as Gaisoulg, Nada attempts to use the armor's power to save his friends from their latest foe. Amidst the battle, Nada sacrifices himself to save Koh and grant him the power of the Max Ryusoul so the latter can defeat Uden and save the others.
The Ryusoulgers get word that a giant space dragon is coming to Earth, along with another Druidon general, Pricious, who betrays both Wiserue and Gachireus to use the Space Dragon to destroy their enemies. To overcome the challenge ahead of them, the Ryusoulgers will have to challenge a long-standing Ryusoul Tribe tradition to obtain more power.
As Pricious and his Space Dragon continue wreaking havoc, the Ryusoulgers struggle to overcome the Cliffs of Trials in order to unlock the most powerful Ryusoul combination, with Koh in particular experiencing the most difficulty.
Following their battles with Pricious, the Ryusoulgers strive to train harder in order to defeat their latest foe. However, Towa fails to appear for training and to stop a Minosaur attack. When they investigate, the Ryusoulgers find him on a date.
After Tyramigo accidentally injures a child, he and Koh butt heads over what happened. Just then, Wiserue and Gachireus join forces to overwhelm the Ryusoulgers, and the only way they can stop them is to help the quarreling red champions settle their differences.
Taking advice from the spirit of deceased Ryusoul Tribesman, Seto, the Ryusoulgers seek out the Temple of the Beginning, which only Koh and Canalo are able to enter as they undergo numerous tests. Meanwhile, given one last chance by Pricious to prove himself, Gachireus attacks the city with a Minosaur spawned from his own body. Upon completing the temple's trials, the Ryusoulgers gain the Ryusoul Caliber, which they use to defeat Gachireus once and for all.
With Christmas on the horizon, the Ryusoulgers and Kishiryu are in high spirits. Meanwhile, a jealous Wiserue plots to kidnap all the Santas in the city for being more popular than him and creates a Minosaur capable of transforming Christmas decorations into New Year's decorations.
While a strange fog blankets the city and causes strange phenomena, a Minosaur that has tormented Melto in his dreams suddenly appears in the real world to feed on the Ryusoulgers' fear and become invincible.
After being cast in a feature film, the Ryusoulgers frantically search for the Ryusoul Caliber when it goes missing; eventually finding it in the clutches of Saden, a new Druidon general who has the power to steal their weapons right out of their hands.
The Druidons' leader, Eras, is due to revive any day now. Before that happens, Wiserue sets out to capture the Ryusoulgers and destroy them to prove himself worthy to the Druidon cause.
As Eras begins to revive, the Druidon intensify their attacks while the Ryusoulgers attempt to learn more about their enemies' leader. After hearing Eras' name, Bamba remembers how his mentor, Master Black, turned traitor and destroyed their village to protect the Druidon leader.
As Saden holds Oto hostage and demands the Ryusoul Caliber in exchange, Eras creates another Druidon general, Yabasword. The Ryusoulgers respond by splitting into two groups, with one holding off Pricious' forces while the other storms the Druidon's lair to destroy Eras.
Even with Pricious in control of his heart, Master Black suddenly appears before Bamba and demands to see Seto. Meanwhile, armed with the truth behind Eras' resurrection, the Ryusoulgers move forward with a plan to stop her and the Druidon once and for all.
After Pricious learns the true nature of the Druidon Tribe from Eras, he faces the Ryusoulgers as they learned the only way to reseal Eras is by sacrificing their Kishiryu partners.
Now that she has fully revived, Eras attacks the Ryusoulgers and sends them into a peaceful world without conflict. While exploring this new world, the six knights find themselves questioning the true meaning of peace, why they are fighting as Ryusoulgers, and what Eras is really after.
Free of Eras' perfect world and of their hesitations, the Ryusoulgers and their Kishiryu face off against the Druidon leader in a battle to determine the Earth's fate.