The Indigo Warrior - S1.E1

Kazuma Kenzaki, rides to meet up with Sakuya Tachibana, who is fighting the Bat Undead in a cave. Meanwhile, Kotaro Shirai is exploring the cave to find information about the Kamen Riders and sees Kazuma revert to human. The two riders return to BOARD headquarters where Sakuya questions the chief, Kei Karasuma, what BOARD's intentions are. Upon returning home, Kazuma is evicted and meets Kotaro again who offers Kazuma a place to stay. That night, the headquarters is attacked by the Locust Undead.