Season 1

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.

Ankh threatens to leave OOO for Kazari and the Greeed while investigating the evolution of humanity while Eiji tries to find more about Hina.

Kougami asks for a share of Eiji and Ankh's Medals, while Mezool decides to use Hina's shopaholic classmate to create a new Yummy.

Hina confronts Yamano's shopping addiction when her father goes bankrupt while Ankh confronts Kougami about his share deal of the Cell Medals.

Eiji tries to research a husband bullied by his wife that is being mocked by Gamel while Ankh follows a lead for a missing Core Medal.

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's traveler friend becomes manipulated by Uva into becoming famous as he steals others attributes; while Gotou doubts Eiji's effectiveness as OOO.

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.

Eiji rushes to find Ankh to save Shingo's life while Tamura discovers the truth about what it means to be a surgeon.

Kazari uses a transport truck of Cell Medals, a Core Medal of Ankh and a captured Hina to lure all sides into a free-for-all showdown.

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.

Kazari creates an "evolved" Greeed using the desires of a convict to get back at a traitorous hoodlum and Shiro in order to pursue Ankh.

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.

Uva uses the desires of a troubled father to serve justice for the sake of his son to create a Greeed that assist him in creating this desire.

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.

Ankh starts acting suspicious when a new bird Yummy emerges created to help a washed-up boxer stand in the ring once more.

Akira and a worn-down Eiji work to stop the Yummy before the worn-out Okamura stands in the ring once more against his rival.

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 investigates the truth regarding who Ankh is, while Kazari decides to create a Yummy from Maki's desire to see what he's really made of.

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.

Eiji is summoned to a park owned by a former school friend who wants to be a greater help to his dreams.

Eiji confronts Yuichi about his desire to be the only one to be there for him, even as his Yummy continues to abduct Eiji's allies.

Hina tries to work out what her real dream is when she wins a fashion show while Uva tries to work all sides to regain Mezool and Gamel's Core Medals.

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.

Eiji tries to deal with Akira as he joins with Maki and the Greeed while Shintaro tries to figure some way of winning Birth back to their side.

Ankh worries about his future and the assault of his other self while Chiyoko declares war on a security-obsessed household possessed by a Yummy.

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.

After Ankh is taken back by his body, Eiji becomes resolved to bring him back even with no longer wanting Hina and Shingo involved in this battle.

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.

Although finally restoring himself, Ankh retakes Shingo's body and decides to start collecting Medals for himself even as Eiji tries to stop him.

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.

Gamel rampages thinking that he can still revive the dead Mezool, while Ankh realizes his true desire even with Eiji now standing in his way.

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.