Kase

Kase is a Ventaran who transforms into Kamen Rider Siren and a love interest of Len.
==History==
During the time Adam "betrayed" the other Riders, she quickly took herself and Len out of suspended animation and managed to throw him into a mirror. She was thought to have been lost by both Len and Xaviax. Before escaping, she managed to steal two Survive Mode cards for Dragon Knight and Wing Knight (unable to get her own in time). She battles Xaviax's monsters in secret and slowly makes her way back to Len. She first appeared to fight off Xaviax's minion Mirror Monsters and easily defeats them.
She later crashes the battle between Kamen Rider Dragon Knight and Kamen Rider Axe (before the latter could use his Final Vent on the former). She battled Kamen Rider Axe, which ends with Kamen Rider Axe retreating. She then attacks Kamen Rider Dragon Knight until Kamen Rider Wing Knight appears and reveals that she knows him, when she asks why Len is "protecting Xaviax's Riders." It was revealed that Kase is Len's girlfriend, and they are overjoyed to see each other alive. She decides to test Kit by battling him, and ends up defeating him in a sparring match. She does not accept Kit as the new Dragon Knight and feels that Kit is too inexperienced to even be considered a Rider, but trusts Len's judgment.
She feels uneasy the next time she sees him as she begins to see the similarities in personality that Kit and Adam has, stating that it was the attitude Kit has that started Adam's betrayal. But after knowing his resolve, she accepts Kit as a Kamen Rider and apologizes for her earlier behavior. While waiting for Kit to return, Len and Kase sense Strike and Wrath and manage to save Lacey and Trent, but they are easily overpowered by the Xaviax-powered Wrath and Strike. They are able to escape before sustaining any more injuries. Eventually, Trent gives them the location where Kit is being held and they attempt to rescue him.
They find him being attacked by Wrath and Strike, but manage to save him. Returning to the bookstore, she heals Kit's injured leg. After escaping the No-Men from the bookstore, she shows Kit and Len their Survive Cards, saying they will be necessary as they are no longer fighting amateurs. Soon afterward, Kase is forced to battle both Wrath and a hybrid monster. When her back is turned, Strike uses his Final Vent, venting her. Kase is the eighth Kamen Rider to be vented in the series. Len retrieves his fallen girlfriend's deck and promises revenge for her. Her venting was avenged when Len, using Survive Mode, vented Strike. After Kase was vented, Eubulon transferred her Advent Deck to Maya Young.
Kase is later rescued from the Advent Void by Master Eubulon, and reunites with Len while she is recovering. Afterwards, Maya returns the Advent Deck to her; Kase says that she is proud of her not just for her work as a Kamen Rider, but also as a journalist who exposes the truth amongst the lies. She later speaks with Kit in private and convinces him to give Adam a chance to prove himself like she did with him. After Maya senses something wrong with Adam, Kase and Kit go off to follow Len and Adam. They find the two fighting each other.
She soon finds out from Adam that he had given Xaviax the virus who decoded it and created a vaccine. She forgives him as she realizes that he is needed in the final battle and that he truly is sorry for his previous actions, reaffirming this with Kit. Kase and Kit both distract Xaviax and his monsters from detecting Trent and Maya who both manage to get a mirror inside Xaviax's base. Kase and the others manage to get inside and together with Len, Kit and Adam, fight off Xaviax. Though no match for the mighty General, they fought him off long enough for Eubulon to rescue the other Riders and together, they all use their Link Vents to destroy Xaviax.
During the Epilogue, she continues to date Len as she helps rebuild Ventara and protect Ventara and Earth from remnants of Xaviax's army as well as dangers from other worlds behind the mirrors.
==Kamen Rider Siren==
Kamen Rider Siren
Kase can transform into Kamen Rider Siren using her Advent Deck and V Buckle upon forming a contract with Blancwing. Her Visor, the Blancvisor, is a rapier that also functions as her personal weapon. Siren's kicking power and running speed are average, but her punching power is the lowest out of all of the 13 Riders and she is tied with Torque for the lowest jump height.
Through the use of her Sword Vent Advent Card, Siren can arm herself with the Wing Slasher, a double-bladed staff derived from the edges of Blancwing's wings combined together. Her Guard Vent equips her with the Wing Shield, a shield derived from Blancwing's wings and back. It is able to summon a gust of white feathers and allows her to teleport within short distances so as to confuse and evade enemy attacks. In addition, Siren is always seen with Blancwing's torso mounted on her back, equipping her with a cape.
By using her Final Vent, Siren can execute her finisher, the Misty Slash, which equips her with the Wing Slasher if she does not already possess it. Blancwing then flies behind the enemy and creates a gust by flapping its wings, sending the opponent flying towards Siren, who slashes it with the Wing Slasher.
Appearances: Dragon Knight Episode 21 - 30, 36 - 40
==Contract Monster==
==Equipment==
*Advent Deck - Transformation device and Advent Card holder
*V Buckle - Transformation belt
*Advent Cards - Trinkets that enable a Rider to summon Contract Monsters, access equipment, and use special abilities
*Blancvisor - Siren's Visor and personal weapon that enables her to use Advent Cards
==Vehicles==
*Advent Cycle - Motorcycle used by any Rider to enter the Mirror World
==Behind the Scenes==
===Portrayal===
Kase was portrayed by Carrie Reichenbach her suit actor was Keiko Hashimoto (橋本 恵子 Hashimoto Keiko) in footage for Ryuki, in the series, while in the video game, she is voiced by Laura Bailey.
In the Japanese dub, she is voiced by , who would later portrayed Kiva-la in Kamen Rider Decade and Canaria in Kamen Rider: Battride War.
==Notes==
*Kase and Len were the only Ventaran Kamen Riders' whose Earth twins were never seen (outside of Brian Mace, who was only seen in a novel); Len was never Vented and thus his Advent Deck was never given to anyone else, while Kase's deck was temporarily reassigned to Maya Young while she was trapped in the Advent Void.
*Kase is the only female rider on the team (excluding Maya as she cannot be active while Kase is active).
*Kase and Len only had 3 days together every 11 years due to the two being in suspended animation
*When Kase handed Kit and Len their Survive Mode cards in Swan Song, she stated that she wish she got hers. This confirmed that all the riders must have a Survive Mode card. The other cards' whereabouts are unknown as Xaviax never gave them to the Earth riders and Eubulon never mentioned them.
==Appearances==
==See also==
*Eri Ogawa: The girlfriend of Len's counterpart in Kamen Rider Ryuki
==Navigation==
Category:Female Riders
Category:Adaptation Riders
Category:Heroines
Category:Dragon Knight Riders
Category:Ventara Riders
Category:Dragon Knight Characters
Category:Kamen Rider: Dragon Knight
Category:Supporting Riders