Touma and Mei find a girl who is looking for her brother. When they try to talk to her, she is attacked by Desast and runs away. Why is Desast after her? Meanwhile, as he’s looking for Kanon, Takeru Tenkuji finds survivors of Danton’s experiments and vows he won’t let them be sad like Chloe was. When he goes off to look for more survivors, he runs into Touma and Mei…

Serving as a sequel to Kamen Rider Saber × Ghost, Rintaro joins forces with both Makoto Fukami and Kanon Fukami to take down the remnants of Danton's evil forces.