Imagin (イマジン, Imajin, from "imagine") are a fictional race that are the antagonists in the Kamen Rider Series Kamen Rider Den-O. The Imagin were originally humans from the distant future who lost their physical forms due to an event in the past erasing their own time, becoming dependant on the memories of others in order to survive. Led by Kai, they arrive to the year 2007 to find weak-hearted humans and through them go back in time to find the key figure to the Junction Point, and destroy him so their future can become a reality again. Imagin possess humans upon forging a contract, fashioning a physical form by searching through the host's memory for figures found in folklore and myths. The hosts, recognized by the sands of time spilling from their bodies, are offered a single wish by the Imagin. In exchange, the Imagin is able to dive into the most treasured moment of the person's past. As displayed, however, the host must remember making the contract for the Imagin to successfully travel to the past. Additionally, due to the greatly delicate nature of the contract, if the contract holder forgets or dies before the contract is completed, the Imagin bound to him or her would fade out of existence. Opening the human like a door, a portal is revealed that leads to the appropriate time, severing their ties to the human in the process. From there, the Imagin takes over a host's body or simply manifests itself in its physical form and begins causing massive chaos. In turn, due to the laws of time, everything and everyone destroyed in the past no longer exists in the present. However, as Ryotaro learned in time, the restoration of these things rely on just being remembered.