Kaijū is a Japanese term used to refer to monsters of various types, while world-wide the term is used to refer to monsters of colossal size. The term is also used to refer to a genre of Tokusatsu Shows that showcase monsters attacking cities or engaging each other in battle.
In Kaiju films, "heroic" monsters were rarely seen and it was not until later when television productions began using kaiju which aided the hero, saved civilians, or demonstrated some kind of complex personality. These kaiju adopted many classic monster traits, appearing as the "Misunderstood Creature". Some kaiju hung out with the heroes and provided comedy relief, in contrast to the darker approach to these characters from more mature franchises, like Kamen Rider. Godzilla , arguably, is the most well known of the daikaiju, has played the roles of hero, villain, and force of nature in the course of his existence; one of the few kaiju of any type to be depicted in multiple roles and having those around him react in different ways, depending on how the creature itself was being presented in the films.
- The most powerful kaiju are at times referred to as Daikaiju the prefix dai- emphasizing great power or status and is usually translated as "giant monster."
- Toho has produced a variety of Kaiju films over the years (many that featured Godzilla and Mothra) but other Japanese studios contributed to expanding the genre in Japan by producing Kaiju films and shows of their own, studios including Daiei Film Co., Ltd., Kadokawa Pictures, Tsuburaya Productions, Shochiku, and Nikkatsu studios.