, lit. "Terrestrial Defense Corp. Dai-Guard" is an anime television series, produced and animated by XEBEC, and directed by Seiji Mizushima. It aired from October 5, 1999 to March 28, 2000 on TV Tokyo, ran for 26 episodes. 6 volumes of videos were released on VHS and DVD. The series also had a very brief run (two episodes) on Cartoon Network through Toonami's "Giant Robot Week."
The series is based around three office workers of the 21st Century Defense Security Corporation's Public Relations Division 2 who, with the company's giant robot, Dai-Guard, fight interdimensional alien beings called "Heterodynes". Unlike most giant robot anime, Dai-Guard performs on much more realistic physics, making it heavy, slow, and a hassle to control. Also, the Heterodynes seem to be the least of the 21st Century Corporation's problems as they experience opposition in the form of massive damage claims, lawsuits, rivals and a jealous and antagonistic military who wishes to take back Dai-Guard for themselves.
On February 24, 2018, in the Northwest gap of the Sea of Japan, a giant creature appears and goes on a rampage, destroying a major city and killing countless people before being destroyed itself by a weapon of mass destruction known as an "O-E (Over-Explosion) bomb". In the aftermath, a giant robotic weapon system, code-named Dai-Guard, was developed by the military as an alternative to the future use of such weapons. However, further attacks fail to occur, and no sign of the creatures is seen for the next twelve years.
The company that built the robot for the military is compensated by allowing them to keep the useless weapon as a corporate mascot. However, during a security exposition in 2030, a Heterodyne attacks, and the ill-prepared and unarmed robot is taken into battle due to the headstrong nature of one of its pilots. However, that same pilot's same headstrong nature, combined with the talents of his fellow pilots, enable Dai-Guard to be victorious against multiple Heterodyne attacks (to the chagrin of the military that spurned the '100 foot sales gimmick').
Heterodyne are mysterious entities formed from dimensional quakes all around Japan. They form from crystalline hexagons called "Fractal Knots" that act as their nucleus and form into bodies using the matter around them. Although fractal knots replicate themselves indefinitely, if the original is destroyed it will immediately reduce the rest of the body into ethanol. Aside from traveling through dimensions, having Fractal Knots, and being attracted to electromagnetic hot-spots, they have very little in common with each other.
As the Heterodyne are a dangerous and adaptable foe yet not an ineffable enemy, potent weapons are developed by the corporation's technical support teams. The grudging assistance of military advisors lead to the discovery of clever tactics, and Dai-Guard's alien fighting soon begins to take a backseat to the bureaucratic troubles and office politics that the Corporation faces. Although everyone involved with 21st Century and the Anzenhosho Army (ANPO) shares the same goal of protecting Japan from Heterodyne attacks, their own personal beliefs often cause much conflict.
The series ends its run not with the final elimination of the Heterodyne threat, but in an epiphany shared by all of the former rivals: The Heterodyne, although a threat that must be faced with impressive technology, are simply yet another disaster to be faced in a dangerous world, no different from earthquakes or typhoons. In a disaster, it is pointless to argue over who is in charge, as deliberating over such trivial matters could cost human lives. There is no need to force a controlled peace or suppress conflicting opinions in order to apply personal solutions when different people have their own specialties that can contribute to the whole operation. The final episode suggests that Heterodyne will never stop appearing, making teamwork between the Army's new team of Kokubogar units and Dai-Guard a necessity.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』