What is the Reason Go Shijima Fights?

Shinnosuke and the rest of the Special Unit are now more confident thanks to the new Ride Booster support vehicles. Kiriko and Go eventually get into an argument whether to trust Chase or not as a Kamen Rider. Later, Shinnosuke joins a joint investigation from the Central Government Office where Brain (in his human form) tries to frame Shinnosuke, whom is already aware of Brain's involvement in the division. Meanwhile, a girl named Yoriko seeks Go's help as her brother was attacked by a Roidmude.