What happened to Shoutarou, Phillip, and Sokichi Narumi on the night "Kamen Rider W" was born?..... After the escape from Shadow Fuuto and subsequent battle, Tokime resolves herself seeking out the truth behind the origins of Gaia Memories, Kamen Rider W, and her connection to that shadowy city. Later than night, Shoutarou has a heart to heart with Tokime recounting his painful past and fateful night where everything began, named by Phillip: "Begins Night". A story when dopants started to appear in Fuuto and how a young Shoutarou became private investigator Sokichi's assistant, and tried to follow in his footsteps.