Yukiaki Kiyama

Deputy Officer of the United Nations Alliance, Simon Marcus, who aims to conquer the world with the terrorist organization Downfall along with the mad scientist Keiji Uraga, attack the Kamen Riders with overwhelming strength. It is only on Kamen Rider Grease that the enemy's abilities did not work. In order to defeat this new enemy and rescue Misora, Kazumi Sawatari must create a new item ... but it is told that it requires the life of his friends, the Three Crows. The ultimate decision must be made.

Annual Kamen Rider stage show featuring the cast and characters from Kamen Rider Build. This Final Stage & TV Cast Talk Show special event took place after the show’s run, and included In its first half an original stage show story that featured Build, Cross-Z, Grease and more from the TV show, complete with lights, sounds, and special effects. In its second half, there was a talk segment with various cast members from the show. The event was held on October 13-14, 2018 at the Nakano Sun Plaza Hall, in Tokyo.

After the end of the civil war that tore apart Japan, the new governors of Touto, Hokuto and Seito work together to reunify the country. However, they are actually members of an extraterrestrial race called the "Blood Tribe" (the same species as Evolto), who assumed their government positions as part of a plan to destroy Earth as they have done to Mars and other planets before. Considering Sento Kiryū (Kamen Rider Build) a major threat to their plans, the Blood Tribe manipulates his friends and other civilians into attacking him. With even his close ally Ryūga Banjō (Kamen Rider Cross-Z) now against him, Sento must fight to survive and stop the Blood Tribe's plan from succeeding.

Kamen Riders Build and Ex-Aid team up with the legendary heroes of the Heisei Generation - OOO, Fourze, Gaim, and Ghost.