"How were Gaia Memories created?" "Why did W begin to fight?" To answer Tokime's questions, Shoutarou quietly begins to tell a story. He speaks of his meeting and parting with a man he admired and called his old man—his mentor, Soukichi Narumi. Mysterious people called Dopants, who utilized the powers of Gaia Memories, had begun appearing in the shadows of Fuuto, the windy city. A young Shoutarou had become an assistant of the detective Soukichi and, though called half-baked, began to follow in his footsteps. Unaware that, in addition to his detective work, Soukichi was secretly acting as Skull, Shoutarou began to grow frustrated with his mentor. That was when the Narumi Detective Agency received a phone call—a request from Hell inviting Shoutarou and company to a fateful night! When Shoutarou tracked down Soukichi to deliver the "trump card" bestowed by the mysterious caller, what did he see? Shoutarou and Philip. The one detective made of two and the night when Kamen Rider W began. That whole story will finally be revealed. (Source: Official site, translated)

In the great Garubado Empire, a lethal weapon is in the process of being manufactured, but is stolen and subsequently lost in battle. Now the Empire is looking for this weapon: a girl that can call forth the "Dragoon" power. She has amnesia and is found by a wandering swordsman in training by who vows to help her find out who she is and why she has such a strange power.

St. President school is one of the most wealthy schools around. Everybody in that school respects the Yukan club, the most popular and richest group in the school. This includes Shouchikubai Miroku, Kenbishi Yuuri, Kikumasamune Seishirou, Hakushika Noriko and Kizakura Karen. They go through dangerous adventures to save their school, and of course, just to kill their spare time.

The story of a young girl and a young dragon. Naturally, they are the best of friends, and naturally the rest of the world is against them both. However, when demons decide to trash their world, they side with those who have always been against them.