Eight years have passed since Kamen Rider Saber's transformation, Kamiyama Touma, and other swordsmen desperately tried to save the world. Touma adopted Xiaolu, a boy who lost his parents due to being involved in a war. His good friend Mamiya and editor Sudo Mei also helped take care of him. Touma wanted to make up for Xiaolu's lost father's love, but he could not heal his trauma. He was 11 years old and still did not smile. On the other hand, Kento Tomikamiya, who became a translator, was about to marry Tachibana Yuina and was living a fulfilling life every day. However, at this time, strange things began to happen around the swordsmen, and the holders of the holy sword disappeared one after another. Just as Shindo Rintaro began to investigate the matter, Kamen Rider Bajian Amazing Siren suddenly appeared. After the transformation, Shinjiro Shinozaki claimed to be Rintaro's father, which made Rintaro upset. In addition, Kento ran into Bajian, and Xiaolu did not return from school, and Touma, who went to find Xiaolu, was also attacked by Bajian. What kind of terrible power is hidden in the book of Amazing Siren Fantasy Control? Time flies, and what awaits Fei Yuzhen and his companions is the greatest and final suffering!