Shoutarou Hidari, a hard-boiled private investigator from the Narumi Detective Agency, lives for the sake of protecting the peace in the city of Fuuto alongside his inquisitive partner, Philip. One fine night, Shoutarou encounters a mysterious woman named Tokime, who is soon linked to several cases of homicide and theft. Shoutarou's investigation leads him to people using "Gaia Memories"—memory units similar to thumb drives holding vast amounts of data—to turn into formidable beasts called "Dopants." While the majority of Gaia users were put down by the detective team in the past, a number of them still remain, posing a great threat to public safety. Once more, Shoutarou and Philip, Gaia users on the side of justice, must fight as Kamen Rider W—the renowned hero safeguarding Fuuto—to eradicate the nest of villainous Dopants, all while uncovering Tokime's true identity and confronting the long-forgotten past.

A VHS only special episode. Also known as Episode 95.

In celebration of 20 years of , Studio Pierrot posted an anniversary PV on their YouTube channel. The PV is a compilation of newly reworked scenes from containing new animation.

In the near future, technology has made a few leaps and bounds, and videophones and constant wireless internet access are available to everyone. However, it would seen that the government has been careless and a skilled hacker was able to break into the national information archive. Using the data held there he creates the Platonic Chain website for people to discover information about themselves and their friends. Words start to spread quickly that there is a site that enables you to look up anything. Coincidentally, three young girls, Hitomi, Rika, and Kanae, are able to access the site. This is a 15 minutes special to the TV series, Platonic Chain.