Whilst investigating the urban legends of the Undead, Kotaro Shirai stumbles upon the two Kamen Riders of BOARD.

BOARD is in pieces. Left reeling by Tachibana's betrayal, Kenzaki is forced to respond to another Undead attack.

Hirose manages to get access to Chief Karasuma's hard drive. While they search to find him, another Undead attack brings Tachibana back to the frontlines.

Tachibana reveals the truth behind the BOARD attack, and warns Kenzaki that the Rider System will destroy his body.

Hearing an urban legend about a cave where you can hear the voices of the dead, Amane drags Kotaro and Kenzaki along. However, the Centipede Undead attacks...

Kenzaki discovers the link between Amane and Chalice. An enigmatic man appears with the goal of capturing the Rider System users.

The enigmatic man invites Hajime to see his research material - the captured Kenzaki.

Narrowly escaping the Undead experiment, Karasuma reveals the truth about the revival of the Undead.

While Tachibana questions his ability to become Garren and fight the Undead, Hajime struggles to understand his humanity.

Tachibana's "sickness" is cured and he is able to transform into Garren once again, but at what cost?

With the acquisition of a new Ace card, a new Kamen Rider belt was created. Several people were selected to become this new Rider, but none were able to transform. Shirai is greatly troubled since his sister and Amane are in constant danger with Hajime's presence. Tachibana also meets the Peacock Undead and faces him for the last time. As Garren, Tachibana successfully avenged his girlfriend when he defeated and sealed the Peacock Undead.

After sealing the Peacock Undead, Tachibana decides to return his buckle to Karasuma. After staring at the club change card, Shirai falls under control of the Spider Undead and attempts to transform. Kenzaki stops him but the belt vanishes in the commotion. Karasuma leaves for Tibet to find information to help them. Mutsuki finds the belt and falls under control of the Spider Undead. Chalice finds the Dragonfly Undead and Blade follows him. Chalice fights the Undead while the humans are around, not thinking about them. Blade becomes unsure whether him and Chalice could fight side by side, but after questioning, Chalice refuses as fighting alone is all he knows how to do. After Chalice seals the Undead, they are attacked by Leangle.

During their fight, Leangle unseals one of Blade's and Chalice's cards. Leangle then reseals Blade's card as his own. Kenzaki asks Hajime if he's alright, but he moves away and repeats that he won't join anyone.

While fighting Blade, Leangle unseals three more of Blade's cards. Leangle suddenly reverts to Mutsuki, who was unaware of what he was doing, and Kenzaki takes his belt away.

Kiryu beats Chalice and tells Tachibana to fight. As he leaves, the Undead leave as well. Aikawa returns to the Kurihara family wounded.

Kenzaki and Tachibana try finding Mutsuki to get the belt back, but he escapes them. Mutsuki decides to gain control of Leangle.

Tachibana and Mutsuki arrive as Chalice seals the Undead. As Chalice fights Garren, Leangle takes control of Mutsuki again, but the fight ends quickly.

Tachibana continues to train Mutsuki to overcome the Spider Undead. A friend of the Kurihara family, Kamioka, takes Aikawa on a photo shoot. Garren and Leangle try to seal the Mole Undead, but Mutsuki loses control again and is dragged underground.

Mutsuki overcomes his fear and seals the Mole Undead. Kamioka begins questioning Aikawa's presence at the Kurihara house. The Eagle Undead kidnaps her to trap Aikawa and steals his Change Card.

The Wolf Undead is changing people into werewolves. While fighting them at an amusement park, Leangle meets a group of human Undead Hunters.

The Wolf Undead steals Black Fang as Garren and Blade try to retrieve it. Chalice chases after the Orchid Undead, but Shirai finds her and heals her wound.

The Elephant Undead arrives and defeats Blade and Garren. A strange man, Noboru Shima, shows up at Shirai's house with news from Karasuma.

Mutsuki begins to falls under the control of the Spider Undead again. The Buffalo Undead appears and Garren and Blade rush to seal it.

Leangle fights Shima, but Blade arrives to stop them. While Shima and the others think of a plan, Mutsuki continues to struggle against the Spider Undead.

Azumi, the Serpent Undead, finds Aikawa and fights him with the help of the Tortoise Undead. Garren and Blade show up to help as Chalice staggers away.

The Serpent Undead continues to search for Aikawa. Mikami learns about Aikawa's identity, and tries to get his life back.

While terrorizing people, Leangle is photographed by King, the Caucasus Undead in human guise. Kenzaki asks Aikawa to join them, but Tachibana does not trust him.

Garren arrives to assist Blade and drives off the new Undead. Tachibana tells everyone about Aikawa's identity as the Joker Undead.

Blade and Garren fight over what should be done about Aikawa. Hirose's father contacts Tachibana and shows him the Trials.

Kenzaki realised what was Trial D's motive. He decided to leave town to avoid further harm to other people. Mutsuki battled Hajime into a battle but was attacked by his Fusion Wolf form instead.

Another Trial Undead is hot on Kenzaki's trail, he can also use Kenzaki's moves! Meanwhile, Hajime can no longer control himself and fights assuming his Joker form.

Hajime has been taken over by his Joker form. No longer in control of himself, he cannot see the differences from humans and Undead and it's Kenzaki's King form to blame.

In order to get back Hajime from his Joker form, Kenzaki asks Mutsuki to give him the 5 cards of the Chalice deck that are in Mutsuki's hands, but for that he must let Mutsuki have his Rouze Absorber.

Hajime's problem was solved as he can turn back into a human, but the new problem is on Kenzaki as he and Mutsuki have been tricked by Hirose to fight each other, and Leangle forces Blade to change into King Form.

Yoshido captures Mutsuki to create a new trial named Trial G, based on his Rider data. Meanwhile, Blade was followed by a new Trial, without knowing that it is Yoshito in disguise.

Hirose uses herself as bait to meet Yoshito (Trial B) so that the Riders can destroy him. Unfortunately, Trial G interfered and they have to stop him before it targets Hirose.

Mutsuki wishes that he will be the strongest Rider by fighting against the Tiger Undead but loses instead

After being poisoned by the venom of the Scorpion Undead, one of the two Undead fused into the Titan. Mutsuki attacks his friends and turns into the Category Ace.

Using the abilities of the Chameleon Undead, the Titan tricks the Riders into fighting each other.

All the Riders get together to fight the Titan, and Blade's King form finds a new attack combo, the Four Card.

New Undead are born, and its identified as a fifth ace Keroberos, now all 4 Riders must face this powerful new Undead.

Though Keroberos was sealed, Tennoji reveals his true plan as he fuses with the sealed Undead to become all powerful.

There are only two Undead left and if it's up to Garren, the Joker goes first, but in the heat of battle, will he change his mind or die trying?

With Garren out of the game and Hajime declared the winner, Blade and Leangle are the world's last hope, to seal the Joker.

Kenzaki confronts Hajime in an all out battle with the human race's existence on the line. But can Blade manage to save the world on his own or does the Joker have a plan that will negate the Battle Fight's end game?