Kaiju

is a Japanese genre of films featuring giant monsters. The term kaiju (which comes from the Chinese text Classic of Mountains and Seas) can refer to the giant monsters themselves, which are usually depicted attacking major cities and engaging the military, or other kaiju, in battle. The kaiju genre is a subgenre of entertainment.

The 1954 film Godzilla is commonly regarded as the first kaiju film. Kaiju characters are often somewhat metaphorical in nature; Godzilla, for example, serves as a metaphor for nuclear weapons, reflecting the fears of post-war Japan following the atomic bombings of Hiroshima and Nagasaki and the Lucky Dragon 5 incident. Other notable examples of kaiju characters include Rodan, Mothra, King Ghidorah, and Gamera.

In anime and manga, etc.
This genre is not as common as it is in Japanese live-action movies, but the giant monsters are often antagonists and challenges, especially in the mecha genre. Most often kaiju are crossovers to anime and manga from the live-action film genre.