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.

Kenzaki is captured by the mysterious Isaka, but Tachibana manages to escape the attack. He enlists help from Shiori and Kotaro to search for Kenzaki.

Kenzaki and Karasuma carry an injured Tachibana as they narrowly escape Isaka’s facility. Karasuma reveals the truth about Isaka and his organization.

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? Hajime questions Jin on human emotions.

While fighting Ikasa, the Peacock Undead, Blade is attacked by an unlikely opponent - Garren. Meanwhile with no place else to go, Hajime stays with Jin, but an Undead appears.

It's Blade vs Garren as the Spider Undead—a more powerful, Category Ace Undead—appears. A worried Sayoko investigates the cause of the changes in Tachibana’s body.

Isaka's plans are in motion, as he seeks those marked by the Spider Undead - those with the potential to become his perfect Rider.

As the race to seal the Category Ace continues, Ikasa sets his sights on the one thing that could interfere with Garren.

The Dragonfly Undead kidnaps Amane and her mother, intending to lure Hajime into a trap. Isaka's Rider System is complete, and all that remains is finding a compatible host.

Tachibana retires as Garren, after his involvement in the creation of Isaka's Rider System. That night, the Leangle belt goes missing.

Leangle has found a host, and within minutes reveals a dangerous new ability. Who has succumbed to the power of the evil belt?

Leangle attacks and overwhelms Kenzaki while Kiryu from BOARD reprimands Tachibana for leaving the battle.

Kiryu steals the Leangle buckle and transforms. Drunk with power, he attacks. His fate and Mutsuki’s are now twisted due to their newfound obsession.

Something sinister grows within Mutsuki after he recovers the Leangle belt. Kotaro, still distrustful of Hajime, becomes entangled in an Undead plot.

Tachibana and Mutsuki arrive as Chalice seals the Undead. As Chalice fights Garren, Leangle takes control of Mutsuki again, but the fight ends quickly. After fighting the Capricorn Undead, Kenzaki brings Shirai back home. Tachibana decides to train Mustuki so he can control the belt and Tachibana learns about Mutsuki's nightmares. The Orchid Undead traps Shirai and the Capricorn Undead fights Kenzaki without his belt. Chalice frees Shirai and the Orchid Undead flees. Blade then seals the Capricorn Undead.

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. While on the job at the zoo, Aikawa is attacked by the Orchid Undead. The Eagle Undead arrives and drives the Orchid Undead away. While Mutsuki tries to find a reason to face and seal the Undead, Blade and Garren become overwhelmed by the Mole Undead.

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. Blade arrives and sees Aikawa transform into the Dragonfly Undead. The Orchid Undead attacks Mutsuki but flees. Blade retrieves Aikawa's Change Card from the Eagle Undead and seals him. Kamioka discovers Aikawa's secret but now believes in his goodness.

The Wolf Undead is changing people into werewolves. While fighting them at an amusement park, Leangle meets a group of human Undead Hunters. Leangle, Blade, and Garren encounter the Wolf, Orchid, and Elephant Undead, but they all escape. The Undead Hunters meet with Kenzaki and Garren to discuss an alliance. They help the Hunters complete a new bike, Black Fang.

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. Kenzaki and Tachibana find Shinmei, the leader of the Hunter, and discover that he is the Wolf Undead, so they chase him to the docks and seal him. Chalice finds the Orchid Undead and seals her.