It premiered following the finale of Kamen Rider Decade on September 6, 2009,[1] and aired alongside Samurai Sentai Shinkenger in TV Asahi's Super Hero Time programming block.

[2] The series is notable for being the first installment in what's popularly viewed as Heisei era Kamen Rider's second phase by fans.

Drama actor Renn Kiriyama, who made his acting debut as Bunta Marui in Musical Prince of Tennis: Absolute King Rikkai feat.

Hikaru Yamamoto, who made her acting debut in Watashitachi no Kyōkasho as Chiharu Nobue, portrays the female lead Akiko Narumi.

However, this peace is undermined by the Sonozaki Family, who sell mysterious flash drive-like devices called Gaia Memories to criminals and other interested parties.

To make matters worse, the Gaia Memories can cause their users to go insane, to the point where they could die from using the devices unrestrained.

After the death of his boss Sokichi Narumi, the self-proclaimed hard-boiled (actually half-boiled) detective Shotaro Hidari works with the mysterious Philip, who possesses a set of purified Gaia Memories, to investigate Dopant-related crimes in Fuuto.

With their Gaia Memories and the Double Driver belts, Shotaro and Philip transform and combine into Kamen Rider W to fight the Dopant menace and keep Fuuto safe.

While joined in their fight by investigator Ryu Terui, who transforms into Kamen Rider Accel, the mystery of Philip's past, his relation to the Sonozaki Family, and their Museum organization are revealed.

To tie into the show, TV Asahi, Toei, and Avex Trax have produced the Wind Wave FM Internet radio station.

Only one of the shows, Wakana's Healing Princess (園咲若菜のヒーリングプリンセス, Sonozaki Wakana no Hīringu Purinsesu), also exists within the fiction of Kamen Rider W. The other programs, DJ Hurry Kenn's FU-TO Hit on Groove music show and Tsuyoshi and Ayano's Head Wind: One-Game Match!!

The film expands on the origins of Kamen Rider W, featuring guest star Koji Kikkawa as Shotaro's mentor and Akiko's father Sokichi Narumi.

[17] Kiriyama and Suda made cameo appearances, reprising their roles as Shotaro Hidari and Philip in the 40th-anniversary film OOO, Den-O, All Riders: Let's Go Kamen Riders (オーズ・電王・オールライダー レッツゴー仮面ライダー, Ōzu Den'ō Ōru Raidā Rettsu Gō Kamen Raidā).

As part of the special features on the DVD releases, a series of short films are included called "Shotaro Hidari Hard-Boiled Delusion Diary" (左翔太郎ハードボイルド妄想日記, Hidari Shōtarō Hādoboirudo Mōsō Nikki) in which Shotaro daydreams about what life would be like if he, Akiko, or Ryu acted differently.

At several planetaria throughout Japan, Toei had produced a film called "Kamen Rider: The Fearful Global Warming Plan" (仮面ライダー 恐怖の地球温暖化計画, Kamen Raidā Kyōfu no Chikyū Ondanka Keikaku) to teach children about global warming (with narration by Hirohiko Kakegawa).

[25] The Hyper Battle DVD for W is titled Kamen Rider W Hyper Battle DVD: Donburi's α/Farewell Beloved Recipe (仮面ライダーＷ（ダブル） 超バトルDVD 丼のα／さらば愛しのレシピよ, Kamen Raidā Daburu Haipā Batoru Dī Bui Dī Donburi no α/Saraba Itoshi no Reshipi yo).

Fuuto PI (風都探偵, Fūto Tantei) is a manga sequel that has been serialized in Big Comic Spirits weekly magazine since August 7, 2017.

[30] Some of the cast who has previously voiced their characters in the video game Kamen Rider: Memory of Heroez reprises their roles.

This song, as well as "Glorious Street (Eikō no Michi)", and "Extreme Dream" have been included in the complete CD box set.

The newest group, the visual kei band Wilma-Sidr, is named after Hurricane Wilma and Cyclone Sidr.