When Ryotaro and Momotaros are injured in a fight with an Imagin, Kotaro, Kamen Rider New Den-O, and his Imagin partner Teddy return to help solve the case of a stolen ticket and the mystery of a young woman’s doppelganger! But Owner shatters their partnership when he creates a new contract with Teddy, as the Mantis Imagin rampages! Can Kotaro overcome his loss and discover the truth behind the two Mikus?