A mysterious arm reawakens the Greeed from their slumber and decides to use Eiji Hino, a cheerful wanderer, as his means of getting back what he desires as Kamen Rider OOO.
Ankh explains the Greeed and the purpose of the Medals to Eiji, even as the human desires to merely use his new power to fight for good instead of for selfish needs.
Ankh becomes troubled when Eiji prevents him from eliminating his possessed body's sister while another Greeed uses a man's gluttony to create more Medals.
Eiji gets to the root of the Komoris' problem involving greed and loss of ambition while Ankh fights for survival after a failed confrontation with Uva.
A serial bomber tied to a nest of Yummies leads to Eiji to reveal his past to Hina and forces him to encounter a strange man he believes is Mezool's victim.
Eiji must figure the means of stopping the mad bomber and his Yummies to prevent any more lost lives, even with Maki observing the creation of his worker's monsters.
Eiji teaches a lesson to Tsukuba and Gotou about going forth to gain what is desired; while Ankh tries to figure a way to manage the flying Ageha Yummy using Gamel.
Ankh becomes sick of dealing with the problems of working with Eiji as Kazari targets a famous surgeon who believes she is not getting the treatment she deserves.
Maki and Kazari experiment with Gamel in determining the use of a Greeed for a Core Medal container as Eiji approaches Kougami in finding out more regarding the artificial beings.
Eiji and Ankh try to figure out Akira Date, the man who has become Kamen Rider Birth, as Uva creates a peculiar Yummy from a kendo girl who wishes to be stronger.
After a second Yummy splits off from the original with a different motive, Eiji and Akira must work to figure the true desire Rie held in order to figure how to truly destroy the creation.
After being abandoned by Ankh desiring the return of one of his Core Medals from Kazari, Eiji is found by the cowardly hoodlum Yasu while he continues to ponder if his partner can really be trusted.
Eiji and Shintaro work to try and stop Susumu and his son from going too far as they use the power of their Yummy to attack greater targets for the sake of justice.
Akira decides to bond with Eiji to investigate his travels while Kazari slowly awakens the sleeping desires within the scientific sister of a beauty company president.
As Eiji becomes smitten with the elder Yumi sister, Akira tries to reach out to her sudden obsession with being the most beautiful under her awakened desire.
Kougami commands the cast to make a Kamen Rider movie in celebration of the franchise's 1000th episode, leading to a surviving Shocker Combatman to gain a Yummy for his revenge.
As the movie continues to have complications, Sendou discovers the prices of making a deal with an enemy who takes advantage of his pride of who he is.
Eiji and Akira force Ankh to reveal the truth about OOO and his incomplete revival, while Maki reveals to Chiyoko the connection with his older sister.
Hina's friend asks Eiji to help discover who has been helping paying her family money anonymously, while Maki reveals a shocking discovery he took from Kougami.
The truth behind Eiji's philosophy on life is revealed as he becomes the container of the mysterious Purple Medals and faces an assault of new dinosaur-based Yummies.
Ankh tries to figure his position with Shingo's sudden reawakening and the difficulties with the return of Mezool and Gamel while Eiji tries to deal with the dream-shattering Yummy.
Gamel and Mezool work together to create a Yummy that make people tired but sleepless while Shintaro confronts Akira about the bullet in him and its effects as Birth.
As Yumemi becomes a police-state controlled by the Shimoda family and their Yummy, Eiji tries to prove to Ankh on whether or not he is still needed around.
Doctor Maki approaches Eiji about the truth of the Greeed, themselves and the Purple Medals within them while working with Ankh to regain his final desire.
Kougami reveals the importance of Eiji as the container and the danger of the Purple Medals, while Ankh unites the Greeed in an effort to stop him and retake their Core Medals.
Eiji and Shintaro invade Maki's mansion in hopes of reclaiming the Medals, while Mezool continues to ponder the truth of emotions to a increasingly disgruntled Ankh.
Eiji's realization of desire and his Purple Medals forces him to take anything in his way, including Ankh and a final offer from Kougami to become the OOO Vessel.
Having finally taken the burden to becoming the true OOO, Eiji fights to prevent Doctor Maki from realizing his "perfect end" while working to reach his ultimate desire of being there for others and having others be there for him.
