Series: Kamen Rider Decade
Ai, Mai and Mi are Rank 8 employees of BOARD, serving under Tsukasa as the kitchen staff in preparing the food for the higher ups.
|Kazuma Kendate / Kamen Rider Blade
Kazuma Kendate is a Rank Ace employee of BOARD who has the ability to transform into Kamen Rider Blade with the sealed Beetle Undead. However, due to his ranking, Kazuma is prideful to the point of seeing himself to be invincible. It is not until after he gets demoted while Tsukasa arrives that he realizes that ranking is not everything and that followers are just as important as leaders. Soon after helping him with the crisis occurring in his world, Kazuma thanks Tsukasa who is confident that he would look after the Ace Lunch. He sometimes calls Tsukasa "cheese", rather than "chief", though it is not known if this is made purposefully or not. Kazuma later appears in the World of the Rider War as his reality is absorbed into it, leading his Rider comrades against Wataru's. Though at first he refuses to aid Tsukasa and Yusuke, Kazuma has a change of heart and joins in the fight against Super Apollo Geist with Kamen Rider Garren before the villain causes more worlds to merge into the World of the Rider War, destroying the World of Blade which causes its Riders to fade away as a result. However, he is resurrected following Tsukasa's death in Kamen Rider ? Kamen Rider Double & Decade: Movie War 2010 and helps in reviving him and battles Super Shocker, assuming King Form as a result from Decade's K-Touch.
|Sakuya Hishigata / Kamen Rider Garren
Sakuya Hishigata is a Rank Ace senior employee of BOARD who has the ability to transform into Kamen Rider Garren with the sealed Stag Undead After Kazuma's demotion, he starts treating him badly until he himself got demoted after losing his Rider System to Chalice. His life energy is then used by Hajime to create the Joker card.Garren later appears in the World of the Rider War, though it is unclear whether Hishigata survived the incident in his World, or if a new Garren was chosen. This Garren eventually disintegrates together with Kazuma in the aftermath of Apollo Geist's merging of the Rider Worlds.
|Mutsuki Kuroba / Kamen Rider Leangle
Mutsuki Kuroba is an employee of BOARD, originally Rank King but recently promoted to an Ace who has the ability to transform into Kamen Rider Leangle with the sealed Spider Undead. After he is promoted to Ace and Kazuma is demoted, he starts treating him badly while developing a superiority complex. Mutsuki is the last Rider to lose his Rider System along with Hishigata, learning of Chalice's true identity as he and Hishigata have their life energy used by Hajime to create the Joker card. Leangle later appears in the World of the Rider War, though it is unclear whether Kuroba survived the incident in his World, or if a new Leangle was chosen. This Leangle was killed by Wataru, grief-stricken over the death of Rising IXA.
|Hajime Shijo / Kamen Rider Chalice
Hajime Shijo is the president of the BOARD Corporation who secretly uses the sealed Mantis Undead to assume the form of the legendary Kamen Rider Chalice. Because he is more interested in business ethnics, Hajime sees himself as the only thing keeping BOARD alive by offering his company's aid once paid by the government. Furthermore, he conspires with Kamata by taking the other Rider Systems to begin a joint plan to take over the world by creating the Joker card from the DNA of all four Ace Undead. Being unable to get Kazuma to give him the Blay Buckle by normal means, Chalice makes his presence known during Decade and Blade's fights against the Paradoxa Undead and the other BOARD Riders, stripping Kazuma of his Blay Buckle before fighting Decade until Todoroki's sudden appearance. But Hajime escapes with the Garren Buckle as well, later taking the Leangle Buckle with his identity exposed to Hishigata and Mutsuki whom he adbucts and sacrifices to complete the Joker card. Assuming the form of the Joker, Hajime meets his end at the hands of Blade and Decade.
|Kamen Rider Todoroki
Arrives to fight Decade in the World of Blade.
|Kamen Rider Ryuga|
The Undead are a race of monsters that are accidentally released from their seals and go on a rampage. Among them, there are several specialized Undead: Category Aces, the Royal Club, and the Joker. Several Undead also appear in the first episode when Natsumi is trapped within the changing dimensions. They include the Lizard, Pecker, Squid, and Caucasus Undead.
In Episode 8, the Eight of Spades Undead, he terrorizes humans until Kazuma and Hishigata confront him before receiving clearance to transform into Blade and Garren. In the end, the Buffalo Undead is defeated by Blade's Lightning Blast before being sealed into the Magnet Buffalo card.
In Episode 8, the Jack of Clubs Undead, he is destroyed by Decade using Ryuki's Strike Vent.
In Episode 8, the Queen of Spades Undead, he aids the Paradoxa Undead until he is destroyed by Decade's Dimensional Kick.