Dai-Guard: Checks and Balances of Terror

12 years ago, a strange enemy from another dimension arrived and destroyed Tokyo who was almost completely immune to traditional weapons. To combat this alien menace, the government built the giant robot Dai-Guard. Now, years of peace have made Dai-Guard a useless anomaly, and the government foists the robot off on the 21st Security Corporation, a civilian corporation. In these episodes, the 21st's employees show the Heterodyne invaders that a little heart easily outweighs their slightly superior technology. However, the corporation's success could be short-lived if it is forced to lay off its employees.