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.

Confronting a mysterious enemy, the Pteranodon Yummy, Kamen Rider W receives aid from Ryu, who has infuriated Akiko by being too busy to attend her wedding! Akiko demands to know why he even became a Kamen Rider in the first place and the Pteranodon Yummy as it uses the Memory Memory on her to give her the answer to her question. Meanwhile, at the Kougami Foundation, Kousei Kougami talks of the most avaricious man in Japan, Oda Nobunaga, whose final resting place was found. With Doctor Maki overseeing the process, Kougami commissions the creation of a Cell Medal homunculus based on Nobunaga himself. Later, Kamen Rider Core begins to destroy the area as Kamen Riders OOO and W team up to fight the enemy. However, Kamen Rider Core proves too powerful and the two go underground to destroy the Gaia Memory’s source of power to even the odds.

Shiori, a young woman aspiring to work as a fashion magazine editor, is hired by the publishing house of erotica for men. There, she finds herself surrounded by salacious photos and indecent language. However, some of Shiori's earlier enthusiasm is regained through editor-in-chief Ms. Sawaki and pornographic actress-cum-columnist Haru; with their help, she develops an interest in erotica that she uses to hone her writing talent. One day a blunder that could spell the company's end tests the limits of Shiori's mental state. Physically exhausted from the high demand of the job, she is subject to one last shock that pushes her close to the edge.

The year is 2021 and the world is in a state of chaos and fear. The ancient king OOO has come back to life after 800 years of dormancy. As the Kougami Foundation mounts a human resistance, Eiji Hino returns to Japan, believing he has at last found the means to revive the Greeed Ankh...

While testing the Birth X Driver, Shintaro Gotou is shunted into a parallel world filled with many familiar faces in unfamiliar places. Can he master the secrets of the Birth X Driver and return home?

Kamen Rider OOO: Final Stage is the final stageshow of Kamen Rider OOO, taking place during the TV series' finale. King OOO's soul (the first OOO) has been travelling parallel worlds after the death of his body. In order to regain his original power he has sealed away every OOO in each parallel world until he becomes the ruler of the parallel world called World of Putotyra. He teleports Eiji Hino, the last OOO who resides in King OOO's original parallel world, and fights him.