Advent Calendar

is the first Kamen Rider Ryuki Edition of S.I.C. Hero Saga, published in Monthly Hobby Japan magazine. It featured original characters and his Mirror Monster . Advent Calendar ran from August to December 2004.
;Advent Calendar chapter titles
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==Synopsis==
The story opens with Ren and Yui talking, the latter explaining how as a child, Shiro often read to her Aesop’s fable “The Birds, The Beasts, and The Bat,” about a group of birds and beasts who fought, with the Bat being indecisive and never truly helping either side. Ren sees himself as the Bat, being indecisive due to wanting to become cold to win the Rider Battle and save Eri, yet starting to hesitate ever since Shinji arrived.
After a Rider fight, Ren and Shinji return to Atori and are scolded by Yui’s aunt for always disappearing, and tells them to prepare for work. She mentions that Yui’s been gone since morning, which shocks the two since they assumed she went home after the Rider fight. Shinji leaves Atori in a rush but unknowingly drops his cell phone. Ren picks it up and when it rings, he answers it and sees it’s Asakura, who’s taken Yui hostage and demands Ren meet him at the dock warehouse to settle their fight. Ren had initially approached Yui as a plan to advance in the Rider Battle, but now saw her as an important person who was comparable to Eri. Asakura promises to give Yui back if Ren wins.
Ren became determined to save Eri since she didn’t have much time left in the hospital. They got to know each other and started living together since they both didn’t have any relatives. Ren transforms into Kamen Rider Knight Survive and drives to the warehouse on Darkraider in bike mode as Asakura transforms into Ouja. They travel into the Mirror World via Darkraider and Ride Shooter, where Ouja manages to knock Knight off of his bike and disorient him. He then summons Genocider and traps Knight in its jaws, then attacks him furiously with the Evil Whip. The barely-living Darkraider attempts to save Knight and flies into Genocider and only succeeds in making it drop Knight, and dies in the process. Knight thus reverts to Blank Form with the death of his contract monster.
Ouja approaches Knight as Shinji arrives transformed into Ryuki to save him. Shinji is angered by Knight not moving at all and prepares to attack, but Ouja reveals he’s stolen Knight’s Survive Shippu card and uses it to transform into Kamen Rider Ouja Survive. He demands that Ryuki also transform into Survive and fight him. Ouja attacks relentlessly and Ryuki tries to talk him down, but to no avail. Ouja then talks about how all life is like a battle and that it’s in a human’s nature, but Ryuki doesn’t agree. Fed up, Ouja defuses Genocider and sends Venosnaker to bring the captive Yui to the Mirror World. Ryuki is confused for a moment about how Yui can survive in the Mirror World without a Rider suit and thinks there’s something different about her, but drops the thought.
Ouja threatens Shinji to transform into Survive otherwise he’ll kill Yui, but Ryuki frees her by summoning Dragreder to attack Venosnaker. Further enraged, Ouja reveals that he’s defeated most of the other Riders and taken their Contract Monsters, and fuses them all into Genosurvivor. Dragredder is also forcibly merged into the monster. Ouja orders Genosurvivor to crush Ryuki, and when he seemingly succeeds, shows delight at having one Rider left before he can get to Odin. However, Ryuki and Yui survive the attempt thanks to Dragredder still trying to break free from Genosurvivor and making it lose its balance. Venosnaker’s head and Dragredder keep fighting, their combined strength enough to cause large cracks to appear all over the Mirror World, which Ouja is unable to stop. This ends up affecting the real world: cracks appear in the computer Reiko is using, Nanako’s hand mirror breaks, and the windshield on Okubo’s car breaks, causing him to drive into a pole.
The mirror-cracking phenomenon spreads to Tokyo, and with the collapse of the Mirror World imminent, Ouja tries feverishly to make Genosurvivor stop. Ryuki tries telling him to cancel the Unite Vent, but then Zolda arrives. He got annoyed due to the windows on his car breaking and figured something was happening in the Mirror World. He then summons Magnagiga and prepares his Final Vent. Ryuki tells him to stop since Ren is still trapped under some rubble, but Zolda fires anyway and completely destroys Genosurvivor. With Ren’s body seemingly also destroyed with the attack, Shinji screams in anguish and falls unconscious.
Shinji is woken up by Yui telling him to come back to his senses, and he finds that Ouja and Zolda are both dead, with his sword covered in blood. Yui is horrified at what Shinji did, but he doesn’t remember. Yui explains that Ryuki’s colors changed from red to black, and that Dragredder survived but was also black. Shinji had gone mad and fight-happy like Asakura and killed both Zolda and Ouja. Shinji collapses with the realization that it was actually his older brother that possessed him and did this.
It’s explained that Shinji’s (真司) real name was "Shinji" (真二), and that he had an older twin brother named Shinichi who he was good friends with, however Shinichi became unmanageable as he grew older. One day, Shinji got attacked by a hoodlum with a knife, and Shinichi saved him at the cost of his life. The people around Shinji were relieved that Shinichi died and not Shinji, which greatly hurt him. Since that day, Shinji started to act like Shinichi; it was rumored that Shinichi’s spirit started inhabiting Shinji because of his kindness in thinking Shinichi’s death was pitiful, but a doctor diagnosed him with a split personality disorder. After that, Shinji changed his name to obfuscate the connection with his brother.
Yui asks Shinji what he’ll wish for when he fights Odin, and he replies that he’ll just stop the Rider Battle. He’s distraught that people had to be sacrificed to make his wish when he's suddenly attacked from behind by Knight. Knight explains that he never really died, and that the one who fought Asakura earlier was a double created by Trick Vent. Ryuki is happy that Knight is alive, but Knight starts crying as he says he had to win the battle no matter what move he had to make.
Ryuki and Knight fight to the death, the victor unclear and carrying the body of the other. The victor leaves the other to Yui and then calls out to Odin to fight him. The victor makes his wish, not for the lover who’s hospitalized and not for the older brother of the twin who died young, but to bring “this person” back to life.
==Characters==
===Kamen Riders===
Kamen Rider Ryuki 	Shinji Kido
Kamen Rider Ryuga 	Shinji Kido (possessed by Shinichi Kido)
Kamen Rider Knight	Ren Akiyama
Kamen Rider Ouja 	Takeshi Asakura
Kamen Rider Zolda 	Shuichi Kitaoka
Kamen Rider Odin 	Kamen Rider Odin
===Others===
*Dragreder/Dragblacker
*Darkraider
*Venosnaker
*Metalgelas
*Evildiver
*Genocider/Genosurviver
*Yui Kanzaki
*Sanako Kanzaki
*Reiko Momoi
*Nanako Shimada
*Daisuke Okubo
==References==
Category:S.I.C. Hero Saga
Category:Kamen Rider Ryuki