Tanaka

Kamen Rider Alternative is a Dark Rider who assumed the guise of the Negatives World counterpart of Tanaka, Natsumi's high school teacher. Though ordered by Otoya to keep an eye on Natsumi rather than kill her, he intentionally decides to attack Natsumi, resulting in Dark Kiva beating him merciless. Alternative is then later destroyed by Diend. Although referred to as Alternative, the suit is actually that of Alternative Zero.