Sougo Tokiwa and his friends end up in 16th century Japan during the legendary battle between Oda Nobunaga and Takeda Katsuyori after being approached by Go Shijima and Krim Steinbelt to prevent the latter's ancestor from being killed by a group of time traveling observers known as the "Quartzers", who seek to erase Kamen Rider Drive from history. As Woz reveals himself to be a member of the Quartzers, the truth behind Oma Zi-O is finally revealed.