The Bamiyans is an unpopular three-member rock band. The band members have totally different personalities, but share the same passion for rock. These three get together and talk at the izakaya, the Japanese-style pub, have a quarrel at the studio and compete with another band to find their love for rock and dreams for the future.

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.

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...

As the ancient king OOO continues his onslaught on humanity, Kougami gathers his former employees to create a resistance... and introduce a new weapon in the fight!

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?

Movie War Mega Max featured the first seven Kamen Riders (Kamen Rider 1, 2, V3, Riderman, X, Amazon, and Stronger) to commemorate the franchise's 40th anniversary. Trailers for the film shown during airings of Fourze also showed the return of Kamen Rider Double as well as a new form for Kamen Rider OOO. Unlike previous Movie War films, where they were divided into 3 segments, Movie War Mega Max is divided into 5 parts. Like previous Movie War films the secondary Kamen Rider of Kamen Rider Fourze, Kamen Rider Meteor, made his debut in the film.

Mika (Marie Ono), a Japanese-American woman, returns to her native Saitama hometown and becomes a therapist for a "nemuriba" ("a place to sleep").

Leading an expedition in Germany, Kougami unseals the resting place of one of the alchemists that created the Core Medals in an effort to retrieve a set of lost Medals. However, upon the seal being undone, millions of Cell Medals erupt into a tower while creating a magical barrier that causes parts of Japan to flip over. As the alchemist reveals her plans to become a new OOO, Eiji and his friends are thrown into the past and must find their way back home and stop the alchemist before she destroys the world!

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.

A series of net movies that were released by Toei to promote the Kamen Rider OOO summer movie, "Kamen Rider OOO Wonderful: The Shogun and the 21 Core Medals".