In Japan, "robot anime" (known as "mecha anime" outside Japan) is a genre that features the machines as the central plot points. Here, the average robot mechs are usually fourteen feet (4.3 m) tall at the smallest, outfitted with a wide variety of weapons, and quite frequently have tie-ins with toy manufacturers. However, the robots can get up to 500 m tall (as in Bokurano). The Gundam franchise is a prominent example: Gundam toys and model kits (produced by the Japanese toymaker Bandai) are ubiquitous in Japan.
The size of mechs can vary according to the story and concepts involved. Some of them may not be considerably taller than a tank (Armored Trooper Votoms, Megazone 23, Code Geass), some may be a few stories tall (Gundam, Escaflowne, Bismark) and others can be as tall as a skyscraper (Space Runaway Ideon, Genesis of Aquarion, Neon Genesis Evangelion). There are also mechs which are big enough to contain the population of an entire city (Macross), some the size of a planet (Diebuster) and some the size of a large galaxy (Getter Robo, Tengen Toppa Gurren Lagann). Some are even implied to be able to be as large as the universe (Tengen Toppa Gurren Lagann: Lagann-hen). And then there are some that are so big the universe they are in collapses and they fight in the space outside (Demonbane).
The genre started with Mitsuteru Yokoyama's 1956 manga Tetsujin 28-go (which was later animated in 1963 and also released abroad as Gigantor). Its inclusion is debatable however, as the robot was controlled by remote instead of a cockpit in the machine. Not long after that the genre was largely defined by author Go Nagai, into something considerably more fantastical. Mazinger Z, his most famous creation, was not only the first successful Super Robot anime series, but also the pioneer of the genre staples like robots being piloted by the hero from within a cockpit and weapons that were activated by the hero calling out their names ("Rocket Punch!"). According to Go Nagai:
- "I wanted to create something different, and I thought it would be interesting to have a robot that you could drive, like a car."
This led to his creation of the Mazinger Z, which featured giant robots which were "piloted by means of a small flying car and command center that docked inside the head." It was also a pioneer in die-cast metal toys such as the Chogokin series in Japan and the Shogun Warriors in the U.S., that were (and still are) very popular with children and collectors.
Robot/mech anime and manga differ vastly in storytelling and animation quality from title to title, and content ranges all the way from children's shows to ones intended for an older teen or adult audience.
Some robot mechs are capable of transformation (Macross, Zeta Gundam) or combining to form even bigger ones (Beast King GoLion and Tengen Toppa Gurren Lagann). Go Nagai is also often credited with inventing this in 1974 with the television series Getter Robo.
The mecha genre, one of the oldest genres in anime, is still alive and well in the new millennium, with revival OVAs like Getter Robo: Armageddon and Mazinkaiser from the Super Robot tradition, the recent Mobile Suit Gundam 00, Macross Frontier, Code Geass, Basquash! and Rideback from the Real Robot genre, and Reideen, a recent remake of the 1975 hit series Brave Raideen. Other recent anime series in the mecha genre include Heroic Age and particularly Tengen Toppa Gurren Lagann, a Super Robot anime with a few elements from the Real Robot genre.
Not all mechs need be completely mechanical. Some have biological components with which to interface with their pilots, and some are partially biological themselves, such as Neon Genesis Evangelion, Eureka Seven, and Zoids.