Our MC finds out that his school requires him to join a club and during his reluctant search he stumbles upon Tejina-senpai attempting magic tricks in her clubroom. Tejina-senpai has massive stage fright however and so now that she has an audience her attempts are simply comedic.

Seigi, a martial arts trained middle schooler, often feels driven to protect the weaker people around him. One day, he defends a homeless man against some punks, and the man gives him a strange tattoo on his palm in return. The tattoo is a secret weapon produced in the arms race between America and the Serinistan Kingdom. Seigi finds himself in over his head when a powerful girl, using the same secret weapon, violently pursues him in order to retrieve it. His skill at martial arts may not be enough to keep him alive, but will he be able to learn how to trigger the power of his tattoo in time?

Bomb disposal expert Ivan Yeung returns from England and happens to come across a grenade case by accident. Ivan's skills are highly appreciated by senior chemist Ko Yin-Bok and he is invited to join the Forensic Division. Meanwhile, other members of the team are caught in an explosive incident that ends up changing team dynamics.

10 years ago when the Pandora Box was discovered on Mars and brought to Earth, it's activated and creates a Skywall which divides Japan into Touto, Seito, and Hokuto resulting into untold chaos. Along with creating a complex power dynamic between the three regions, the event brings waves of monsters called Smash down on the country, who terrorize and attack the citizens. Sento Kiryu, an amnesiac taken in by a mysterious cafe owner named Soichi Isurugi who provides him with a belt called the Build Driver that allows him to turn into Kamen Rider Build, which he uses to fight the Smash on his own.