|“||I desire everything under Heaven||„|
When the Kougami Foundation discovered the mummified remains of Oda Nobunaga, they used a process to create a Cell Medal based homonculus of the warlord, with the original Nobunaga's memories stored into him. However, during his awakening he escapes from the Foundation scared and confused while beginning to attack descendants of major clans of the Sengoku period who arranged his death as an incomplete Armored Warrior Inhumanoid. He is then placed in Eiji Hino's care who shows him how much the world has changed without any knowledge on who he really is.
He visits a library one day and after spending much time reading through several books, he gains a better understanding of the world. While on a job with Eiji, he fixes a computer bug that the Marshall Software company had much difficulty in, and is given a job in the company. He later then gains control of the company by gaining a majority share and becoming Chairman. At an auction selling his past life's items like the Hatsuhana he meets Kosei Kougami and wins the auction by exchanging it with the stocks he bought from the Kougami Foundation and his personal portfolio. At a ride back to his company he explains his desire to have the world under his control, much like how the original Nobunaga desired control over Japan. Kougami then gives him the Birth System as a present for his desires.
He would use the abilities of the Birth system to fight a Pteranodon Yummy to gain the public's attention and would attempt to kill Yoshino Akechi when he found out she is a direct descendant of the man mainly responsible for the original Oda Nobunaga's death, Akechi Mitsuhide. However after seeing her dance he remembers a dancer from his past life and tries to get her to be his Narashiba. When she refuses, Nobunaga attempts to kill her as the incomplete Inhumanoid only to be stopped by Eiji who proceeds to fight him as OOO. However their fight is interrupted by the appearance of a female Pteranodon Yummy and Nobunaga suffers memory loss due to a Cell Medal breakdown but slowly remembers Eiji.
After a small talk with Eiji, he realizes that he had only lived for his own desires and never paid attention to anything else. Visiting Yoshino in the hospital he heals her injured leg, with the last of his energy while collapsing. Maki then shows up and puts three black Core Medals (Sasori, Kani, and Ebi) into Nobunaga as the final part in the experiment, completing his transformation into the Greeed-like Armored Warrior Inhumanoid. During his final battle with OOO, he recalls Yoshino's dancing and after his defeat at the hands of OOO Sagohzo Combo's Scanning Charge, Nobunaga requests that Eiji give Yoshino a flower from him as he disperses into Cell Medals while the Black Core Medals fly into the distance, resonating with the Memory Memory.
As a revived version of Oda Nobunaga, Nobunaga has a vast amount of knowledge in battle field strategy and is a highly skilled fighter with or without the power of the O Medals. He also possesses the original Nobunaga's ability in business, buying out Marshall Software from his former superiors and making himself chairman. After spending many hours within a library and reading several books, he gains skills such as debugging a computer within seconds whereas an entire company had difficulty and would take a week to fix it.
Armored Warrior Inhumanoid
As the Armored Warrior Inhumanoid, Nobunaga becomes a feared individual with his natural abilities increased greatly. At first he appears in an incomplete form with no face and is armed with a skull decorated sword. His favorite word while in this form is "Judgement" when killing his targets. However, once he is injected with the black Core Medals, his form becomes complete with a samurai-like helmet, a demonic version of the original Oda's face, and a black cape. His attacks in this form becomes more powerful as well such as an energy sword slash demolishing the walls of a hospital where as in his incomplete form, it could only go a minimal distance and was less powerful.
Kamen Rider Birth
- Height: 199 cm
- Weight: 92 kg
- Punch power: 3.5 t
- Kick power: 8 t
- Jump power: 45 m
- Speed: 100m/5s
Like Kamen Rider OOO, Kamen Rider Birth's powers stem from the O Medals that power the Greeed and their Yummy creations. However, Kamen Rider Birth's powers originate solely from the Kougami Foundation's technology developed by Kiyoto Maki to utilize the power of the Cell Medals. On Birth's armor there are capsules called Receptacle Orbs, in which the Birth CLAWs system is installed in until a Cell Medal is used to summon the weapons. However, due to using Cell Medals as opposed to Core Medals, Birth was at a disadvantage against a single Greeed. Kamen Rider Birth's exosuit has originally a self-destruct function built into it. However, the self-destruct function has been disabled by Shintaro Goto when Kiyoto Maki has defected to Greeed side.