Yuji Kiba leads a peaceful life until a truck hits his car, killing his parents and himself. Two years later, he awakens to find his life in ruins — his girlfriend Chie had left him for his cousin, and his house is gone. In rage, Yuji kills his cousin with his newfound powers. Meanwhile, Takumi follows Mari after realizing that they accidentally switched bags. However, the two are attacked by an Orphnoch. Mari attempts to use the Faiz belt to fight, but fails. She pushes Takumi to use it, and he defeats the Orphnoch.

Mari and Takumi continue to reluctantly travel together to Tokyo. Yuji still has not come to terms with what has happened to him. He tries to kill himself but finds he can't. He meets up with his old girlfriend thinking they can start over. She turns on him when the police arrive to talk to her about his cousin's death. He later kills her.

Keitaro and Takumi take Mari to the hospital after the battle with the Ox Orphenoch. Meanwhile, Akai, the Cactus Orphenoch, kills a fuel station attendant, much to the annoyance of his partner, Midorikawa.

Takumi, Keitaro and Mari go to see her father as he will know about the Orphenochs. Yuji takes Yuka to see someone who can help her.

While working in Keitaro's laundry business, Takumi burns some clothes. Mari believes that he is distracted due to what happened to his friend.

Yuji fights Faiz as the Horse Orphenoch to protect the Snake Orphenoch and even stops Faiz's finishing attack, injuring Takumi. Naoya abandons the hurt Yuji, despite being saved by him.

The Owl Orphenoch retreats from Faiz. Keitaro tries to get Kazuhiko to see his mother, but he refuses until he can prove to her that he is serious about music. Yuka tries to talk to Naoya but he is accused of killing another student.

Faiz destroys the Scarab Beetle Orphenoch. Yuji and Naoya try to decide what they should do next. Naoya wants to attack humans, but Yuji believes they should protect them.

At the beginning of this episode, Takumi no longer has the Faiz gear. It was surrendered to the Chief of Smart Brain in the previous episode. He appears to be a bit depressed and takes off on his own for a bit. In the meantime, we learn that the Chief has made Naoya the new Faiz and learn that the Chief's philosophy regarding Orphnochs is if they don't attack humans or if they defend them then they are worthless and are to be eliminated. Yuji still considers himself human and doesn't want to attack humans. Naoya calls him out to fight him but hesitates during the fight. Yuji, in Orphnoch form, disarms Naoya bringing the fight to an end. Yuka and Keitaro find him. While Naoya insults Yuka Keitaro realizes the new Faiz is not an ally of justice and takes back the belt. As he runs away with it he is confronted by an Orphnoch. Takumi arrives to save the day. We see a new rider watching from afar.

Takumi is beginning to think that maybe he was meant to be Faiz. We meet members of Lucky Clover for the first time. Chief Murakami ask Jay, a member of Lucky Clover, to take back the Faiz belt and get rid of Takumi. Murakami arranges for Takumi and Mari to be at the same amusement part that Keitaro has taken Yuka to. Takumi has a hard time fighting Jay in Orphenoch form. The new rider makes a brief appearance and fires on Jay at the end. First appearance of Kamen Rider Kaixa.

Takumi and the main girl were able to meet with her friends and teacher from Ryusei School. They discussed that whomever uses the Kaixa Gear will die. They were then attack by an Orphenoch known as Jay. One of the students transformed into Kaixa, just to get the stuffing beat out of him and die. Just then, Takumi as Faiz, saves the day. But this is a hollow victory as the group of students lost their teacher before he had a chance to tell them what happened on the day of the reunion.

Mari, Takumi, and Keitaro begin looking for Mari’s schoolmate Masato Kusaka. Yuji has decided not to attack humans. Naoya is still trying to figure out what he wants. Yuka is trying to figure out Naoya. Naoya decides to be human and date. He drags Yuka out on a practice date. Takumi, Mari, and Keitaro find Masato. As he and Takumi have a fencing battle, Mari’s former schoolmates are attacked by an Orphenoch. They go to rescue them. Masato follows and transforms using the Kaixa belt. He defeats the two Orphnochs .

Masato stayed with Mari as the remaining Ryuseiji went to search for their other partners to find out about the past. Murakami assigned the Lucky Clover to their tasks. Realizing that he was targeted for not wanting to attack humans, Yuji told Naoya and Yuka to decide for themselves on what they wanted to do from now on.

Yuji and Takumi have been knocked unconscious and into the river. Takumi’s Faiz belt was knocked off of him. His friend picks it up. Takumi’s friends find Yuji and Yuji’s friends find Takumi. Each returns to their own friends. The attacks of the Lucky Clover continue. During a fight with Orphenochs, Takumi realizes that Osada is one of them. Masato transforms into Kaixa to fight Osaka who is in Orphenoch form. To everyone’ssurprise, Takumi protects the Orphenoch.

Masato seems to be trying to sow discord between Takumi and his friends. Takumi won't explain why he attacked Masato and defended the Orphenoch. Masato lets Takumi know that he is trying to replace him with Mari and Keitaro. According to him, people who don't like him are in his way.

Masato and Takumi begin by squaring off again. Kusaka thinks Takumi's days as Faiz are numbered. Mari and Keitaro can't understand what is going on with Takumi. Kusaka take advantage of this to make himself look good and to try to get rid of Takumi. Yuji's dead girlfriend's older brother contacts him to get him to help find her killer. He gets turned into an Orphenoch and attacks anyone who seems to be speaking bad about her. Yuji realizes that the older brother has become an Orphenoch and as lost his soul as a human but he can do nothing about him. Takumi fights him. Takumi realizes he had lost his way and strayed from his path. Not all Orphenochs want to live as humans and they must be dealt with. As this episode ends, Kusaka finds out there is a third belt.

Masato went off with his old classmate as they went to find out more about the third belt. Smart Brain continues on their attempts to recover Faiz and Kaixa. Meanwhile, a girl had been followed by an Orphenoch. As glum mood surrounds the Kiba household, Yuji wondered about the identity of the Faiz user.

The battle between Yuji and Faiz ends in a stalemate as the other Orphenoch gets away. Lucky Clover member J is given a final chance to retrieve either belts for the sake of his dog Chaco.

Two of the members of Smart Brain are ordered to get the Faiz Gear back and kill all traitors. Saeko of Lucky Clover meets another Orphenoch that wants to take Jay's spot. Takumi faces off against one of the members while Yuji Kiba faces the other one. Both fights end up the same: defeat, but Takumi's is much worse because the Orphenoch that he lost to took his Faiz Gear and transformed into Faiz to kill Takumi and finish his job.

Takumi and Yuji were blasted away into the river because of the new Faiz. The new Faiz also gloats to the female member of the Lucky Clover that he will take back the Kaixa Gear as well. Kaixa returns to fight the new Faiz and take back the belt. But Takumi gets the belt again with a new gadget that lets him change into Axel Form. Using this form, he defeats the Centipede Orphenoch.

The story begins with Yuji and Takumi fighting each other in Orphenoch form and Faiz form, respectively. Neither know that the other can transform. Masato comes back from his trip. He doesn't say much about it other than that the others from Ryuseiji Tutor are fighting. He continues to push Takumi's buttons. He lets Mari know that he likes her. Murakami suggests training a new member for Lucky Clover to replace Jay. Masato overhears Mari questioning her feelings for Yuji. This upsets Masato. Yuji and Yuka ask Mari to consider going out with Naoya. Yuji and Masato are attacked by Orphenochs. Masato puts on his belt, causing Yuji to realize he is a rider. Murakami and another Orphenoch confront Takumi and Mari, demanding the Faiz belt.

Having accidentally found out about Yuji, Masato announced a truce as they fought Saeko and another Orphenoch that had come to kill them. Realizing the fact Yuji did not know of Faiz's true identity, Masato hatched a plan to use that against Yuji as he learned about Lucky Clover.

Takumi joined into the fight as he witnessed Masato fighting two Orphenochs as Murakami arrived to stop them. Masato revealed his intention to wanting to join Lucky Clover. Yuji wondered what Masato really is. Is he an enemy or ally? Naoya made another decision as he was rejected by Mari.

Smart Brain recovered Faiz and Kaixa as Kusaka was captured. Mari and others sneaked into Smart Brain to save him. While escaping from Takumi, both of them discovered the entrance to the underground Ryusei School. Over there they stumble into a startling discovery.

Kyouji was disappointed about the loss of the belts as he looks for another Lucky Clover candidate. Masato reminds Takumi to keep quiet about what they saw at the school as they met the Ryuseiji later. On the other hand, the remaining Ryuseiji fought over who should keep the Delta belt. A girl appeared at Keitaro as she offered to work part-time. Delta appeared.

Members of the Ryusei School are trying to find the Delta belt and are arguing over it at the same time. Itsuro of Lucky Clover continues to try to kill Yuji. As they are fighting, they run into Keitaro and Saya. Keitaro encourages Saya to run and soon Delta appears on the scene. Everyone thinks that Aki has the Delta belt. Kyosuke and Ken kidnap Mari to lure out Aki, who continues his murderous rampage as an Orphenoch. Aki kills Kyosuke and Ken as Takumi and Masato arrive on the scene to save Mari. Delta arrives on the scene.

Faiz and Kaixa are fighting Aki with little success. Before Delta can join in, Mari intervenes and Aki escapes. Everyone is still trying to figure out who has the Delta belt. They are beginning to suspect that maybe Saya has it. The belt was originally sent to her. Mari and Masato try to arrange a meeting with Aki. In the meantime, Itsuro meets up with Kitazaki. Anyone who Kitazaki touches dissolves. Three crooks found that out when they tried to steal from Kitazaki. Aki eventually meets Masato and Mari. He tells Mari that he has always liked her. By killing her he can completely throw away his humanity and grow stronger as an Orphenoch. He and Masato transform and fight. Takumi arrives to fight Aki as does Saya. Sawada kills Saya and gets the Delta belt. He is made a part of Lucky Clover.

Kitazaki now has the Delta gear. Masato vows to get it back. Kitazaki proposes a bet with the other members of Lucky Clover to see who can kill Yuji first. The winner gets to slap everyone on the arm. This strikes terror in Itsuro who is scared of Kitazaki. Aki goes after Yuji and knocks out Naoya and Yuka. Itsuro arrives and joins in the battle. Yuji manages to get away and is found by Saeko. As Takumi goes to deliver Yuji's laundry, he comes upon the fight and transforms. He immediately attacks Yuji, who is still in Orphenoch form. As they are fighting Kitazaki arrives on Delta's motorcycle. Both get knocked around by Kitazaki and transform back to normal. Yuji realizes that Takumi is Faiz and Takumi realizes that Yuji is an Orphenoch.

The battle between Yuji, Takumi, and Kitazaki continues. Itsuro interferes, allowing Takumi and Yuji to escape. Masato meets up with Aki and tries to convince him to get the Delta gear for him. Aki refuses and they fight.

Masato continues to sow the seeds of distrust between Yuji and Takumi. Takumi fights Aki but hesitates to finish him off. Aki takes advantage of this and fights him off. Aki is still battling his humanity. He agrees to meet up with Mari. When Mari goes to meet Aki she is attached by another Orphenoch. Aki saves her. Masato arrives to fight Aki.

As Masato is about to deliver the rider kick, Mari intervenes. Takumi gets there just in time to save her by blocking the kick with his bike. Takuma tries to steal the Delta gear from Kitizaki. Mari arranges to meet with Aki again. However, before she does Takumi meets him. Aki tells Takumi that Mari is the only one who can help him become human again. When Mari arrives she is attached by Saeko's Orphenoch assassin again. As Takumi battles him he encourages Aki to take Mari to safety. After saving her again Aki punches her hard enough to send her flying into a building. She is hospitalized. Naoya and Keitaro manage to save a child from a fire. Masato makes Yuji believe that it was Takumi that injured Mari.

Masato continues to blame Takumi for Mari's injuries. He believes Takumi's soft attitude about Orphenochs lead to Mari being injured. Takumi and Yuji decide to meet up again to fight. This time they fight until both are exhausted. Kitazaki tries to join in the fight as Delta but both Yuji and Takumi make it clear that this is a fight between the two of them. Kitazaki decides to fight the winner. Kitazaki is losing interest in the Delta gear. After telling Itsuro that he threw the belt away, he gives it to Aki. Takumi decides he no longer has the right to be Faiz and gives the Faiz belt to Keitaro. Both the Delta belt and the Faiz belt both end up being given to Masato.

Takumi wants to revive Mari and Masato knows that the only chance she has lies with Smart Brain. Yuji finds out that Takumi is not the one that injured Mari. Masato wants to give away the three belts for her life, but decides that his mission to destroy Smart Brain is more important than Mari. Takumi goes to the chief of Smart Brain and asks to revive Mari. He says that he'll only do it if he becomes a member of Lucky Clover by killing Aki. However, he says that it's impossible because he is not an Orphnoch. Meanwhile, Masato manages to get the most scared student of the Ryusei School to fight as Kamen Rider Delta and they both try to defeat the Lobster and Spider Orphnoch. Takumi arrives on the scene and, in a dramatic fashion, transforms into the Wolf Orphnoch to kill Aki.

Since only Lucky Clover members have complete access to Smart Brain, Takumi has decided to defeat Aki and become a member of Lucky Clover. He transforms into the Wolf Orphenoch to fight him.

As the story begins, Naoya begins to show an interest in the boy he saved from the fire. Everyone is still in shock about Takumi being an Orphenoch. Mari and Keitaro imagine seeing him in familiar places. Mari is starting to remember the reunion. She remembers that Masato was there even though he insists he wasn't. She and Keitaro get Takumi to come back home. He stays for a little while but leaves again when he realizes that the others are uncomfortable around him. Kyouji tracks him down and shows him a video of him in Orphenoch form at the reunion. As the story concludes, it seems as though Takumi is going to try to defeat Yuji, who transformed into Faiz to protect Mari and Keitaro, to get the Faiz belt back and join Lucky Clover.

Takumi runs from his fight with Yuji, making Yuji think that Takumi is afraid of being the wolf Orphnoch and is trying to kill himself. Meanwhile, Lucky Clover thinks that Takumi will completely throw away his humanity and become one of them. Mari continues to confront Masato about the night of the reunion, but he somehow refuses to tell Mari he was at there. Takumi calls Yuji who comes to meet him, and learns he is running from the Lucky Clover. The episode concludes with Yuji interrupting a fight between Takumi in Orphenoch form and Masato in Rider form.

Saeko continues to pursure Takumi for Lucky Clover. Takumi continues to resist. Mari tells Masato that she trusts Takumi. Masato implies that Mari's memories of the reunion might be true. He tells his friends to be on the look out for Takumi. As Masato's friends are attacked for the Delta belt, Takumi arrives and transforms into Delta to save them then passes out. As the program concludes, both Takumi and Yuji are fighting members of Lucky Clover.

As the story begins, Masato and Yuji come to Takumi's rescue. Later, Masato tells Mari that he doesn't remember everything about the night of the reunion. Masato and Mari both go to see Aki to ask what happened the night of the reunion. He tells them. According to Aki, Takumi came upon the students at the reunion as they were being attached by other Orphenochs. Takumi continues to think it was him until Mari talks to him and returns the Faiz belt. Takumi doesn't want to take the belt as he is still afraid of himself and doesn't know when he will lose his humanity like Aki did. Masato goes off to battle Lucky Clover members. He comes across Kitazaki and battles him. Mari, Takumi and a friend of Mari's come across Masato as he has been beat down by Kitazaki. The women try to transform and fight but have little success. Takumi grabs the Faiz belt and transforms. Mari tosses him a new device to use in the fight. This allows Faiz to change into his Blaster Form.

As the story begins, Kitazaki loses a battle to Faiz. He can't believe he lost. Takumi still doesn't quite believe in himself and gives the belt back to Mari. He then goes to the Lucky Clover bar to deliver a challenge. Later he meets up with Aki who tells him more about what happened after the reunion. He then sucker punches Takumi and takes his place in the fight with Lucky Clover. He calls Mari and asks her to save Takumi. As Aki is fighting Lucky Clover, Masato shows up to fight him. Shuji finally decides to enter the battle with the Orphenochs as Delta and shows up as Masato starts to battle the rest of Lucky Clover. Aki dies as a result of his battle with Masato. As the story comes to a close, Takumi seems to have made the decision to fight along side Masato and Shuji as a human-Faiz.

As the story begins, the three riders transform to fight Orphenochs. Mari catches up to them as the fight concludes and begs Takumi to return home with them. He returns home with her. Lucky Clover wants to recruit Yuka as a member. She is strong and has the potential to become stronger. Yuka, Naoya, and Keitaro volunteer with the kids at an orphanage where Teruo, the boy Naoya saved, lives. Strangers warn the police to quit investigating the “incidents” because they are accidents. Meanwhile, those same strangers continue to follow Yuka and her friends as they head to an amusement park. The strangers seem to be conducting experiments of some sort. Keitaro tries to make a move on Yuka and gets rebuffed. She runs off and is followed by one of the strangers. She is approached by Lucky Clover and is forced to fight to show her strength. Masato and Takumi come to her aid.

The strangers are a part of the police department. They are conducting experiments with the idea that the human component can be extracted from the Orphenochs allowing them to kill the monsters. Yuji and Takumi decide to talk to the police. They believe they can convince them that not all Orphenochs are bad. Mari is afraid that she will eventually become an Orphenoch because of the Smart Brain experiments. Masato assures her that the experiment was a failure. Yuka turns herself into the police in hopes of keeping her friends safe. She is brought to the secret research facility. Takumi and Yuji meet with the police and offer to trade themselves for Yuka. An Orphenoch already at the center rescues Yuka. Takumi and Yuji come upon them and allow the Orphenoch who helped to escape. After Takumi answers Keitaro's call, Yuji and Yuka are surprised by the police. The show concludes with Takumi defending the Orphenoch who saved Yuka.

Yuji begins to wonder if humans and Orphenochs can live together. Osada goes to live with Mari and Keitaro. She realizes that Keitaro is her pen pal. She runs away and the others search for her. The police search for her and Yuji. One of the Lucky Clover approaches her after Keitaro finds her. Yuka transforms and defends Keitaro. He sees her true form. Meanwhile, Yuji and Takumi are fighting off Orphenochs and police that are trying to capture them.

Yuji and Takumi manage to escape. Yuka tells Keitaro she left because she didn't want to be a burden to him and the others. He hugs her and tells her he thinks that humans and Orphenochs should live together and be happy. Takumi and Yuji continue to disagree about humans and Orphenochs being able to live together. During the fight with Bat Orphnoch, Yuka is ultimately wounded by humans and killed by at arms at Saeko.

After Yuka's death, a devastated Keitaro cries and mourns over Yuka. Kiba sees Yuka's dead body and thinks the humuns killed her. Takumi talks with Keitaro and Mari about Yuka. Then the King shows up and kill the man in rage. During a fight with the Bat Orphnoch, Faiz assumes his Axel Form and defeats the Bat Orphnoch, then Kiba changes into Horse Orphnoch and kills the police in a berserk rage and takes the throne of the President.

Murakami is deposed as President of Smart Brain while Yuji Kiba is announced as his replacement. Teruo is confronted by Coral Orphnoch who kills the man before escapes from Tereuo's Orphnoch form. Teruo's frightened that he is an Orphnoch King. Next day with the Coral Orphnoch about to attacks Teruo again in rage, he is defeated by teamwork of Takumi as Faiz's Grand impact and Shuji as Delta's Lucifier Hammer. Later Takumi, Masato, and Shuji confronts Murakami.

After being mortally wounded by Faiz, Kaixa, and Delta's attacks, Murakami offers his life to the Orphenoch King. Smart Lady arrives summoning Masato and Takumi to Smart Brain Headquarters to meet the new President. Along with Shuji, they are shocked to discover that it is Yuji. Yuji catches up with Naoya. The Lucky Clover ambush Takumi and they start to fight when six men in identical suits, Naoya among them, appear and transform into a new mysterious foe using Smart Brain-emblazoned belts. Together they attack Faiz.

After fighting with a Riotrooper with Masato's disease that he will die soon, he confronts Yuji that he will fight the Orphnoch King. Mari talks briefly with Rina before getting kidnapped, once again to lure Masato. Hanagata dies from his rapid evolution. As Masato confronts Yuji that he joined Smart Brain, Takumi, Naoya, and Shuji kill all Riotroopers as Faiz Axel Form, the Snake Orphnoch, and Delta respectively. With Masato killed by Yuji as Kaixa, Mari searches for Masato's whereabouts, but he dies before she manages to find him.

Takumi and Shuji find Masato's ashes; later Takumi relays this information to Keitarou and Mari who are devastated. Rina becomes devastated after hear the news Masato is dead. Takumi confronts Yuji that how heartless he is. As the gang fights Kitazaki assumed his Orphnoch form to avenge Masato's death. Kitazaki is injured by Faiz and Delta. Kitazaki is whipped by Itsuro's Orphnoch form before Kitazaki is executed by Arch Orphnoch, who consumes his body. Takumi comes to the realization that Teruo and the Orephenoch King are one and the same and transforms into Faiz in an attempt to kill him. He stops his punch at the last moment, Yuji then appears, transforms into Kaixa and they duel. Takumi is confronted with his own mortality as he notices his body decaying.

After Yuji changes into Kaixa, he defeats Faiz and Takumi faints at Yuji's side. As Takumi replaced into Smart Brain and turned into an Orphnoch easily. Keitaro and Mari saves Takumi and he and Yuji changed into Faiz and Kaixa, fighting each other.