The story tells the adventures of the boy, 21 emon, engaged in the management of a hotel belonging to his family for years. In his problems, 21 emons is helped by the robot Gonsuke and the little alien Monga.
Follows the fluctuating fortunes of three ronin in feudal Japan who wander from castle to castle, selling their services to whichever lord will fill their rice bowls. Though they use the servants' entrance, they still feel themselves bound by the samurai code of Bushido; and this tension leads to tragedy.
Takeshi Hongo and FBI agent Kazuya Taki fake their deaths when they are attacked by Shocker soldiers during a motocross race. They disguise themselves as Shocker soldiers and infiltrate the main headquarters, but it doesn't take too long for Ambassador Hell to find their whereabouts and trap them. Before he detonates a bomb within the base, Ambassador Hell tells Kamen Rider #1 and Taki that Shocker is preparing a giant laser capable of destroying cities. Our two heroes must escape from the base's self-destruction and stop Shocker from arming their latest weapon. Not only that, they must rescue Tachibana and the racing club, who have been abducted by Shocker's minions.