Go-on (呉音?, "sound from the Wu region") are one of the several possible ways of reading Japanese kanji. They are based on the classical pronunciations of Chinese characters of the then-prestigious eastern Jiankang (now Nanjing) dialect.
History and uses
Introduced to Japan during the 5th and 6th centuries, when China was divided into separate Southern and Northern Dynasties, go-on readings are possibly imported either directly from the Southern dynasty or the Korean Peninsula. This explanation is based mainly on historical reasoning: there was an influx of thinkers from China and Korea to Japan at that time, including both Buddhist and Confucian practitioners. However, there is no historical documentation to conclusively demonstrate that go-on readings are actually based on southern Chinese.
That being said, Shibatani has noted that go-on readings make up the first of three waves of Chinese loans to the Japanese language, the others being kan-on and tou-sou-on (meaning Tang Song sound), with go-on mainly associated with Buddhism 
- Edwin G Pulleyblank (1991). Lexicon of Reconstructed Pronunciation: In Early Middle Chinese, Late Middle Chinese, and Early Mandarin. UBC Press. pp. 487–. ISBN 978-0-7748-4467-3.
- Masayoshi Shibatani (2008). The Languages of Japan. Cambridge University Press. pp. 121–. ISBN 978-0521369183.
Go-on readings are particularly common for Buddhist terms and legal jargons, especially those of the Nara and Heian periods. These readings were also used for the Chinese characters of the ancient Japanese syllabary used in the Kojiki.
When kan-on readings were introduced to Japan, their go-on equivalents did not disappear entirely. Even today, go-on and kan-on readings still both exist. Many characters have both pronunciations. For instance, the name Shōtoku (in go-on) is pronounced as such in some derived place-names, but Seitoku (in kan-on) in others. Both are possible today, depending on what is being referred to.
However, some go-on sounds are now lost. Even though monolingual Japanese dictionaries list a complete inventory of go-on for all characters, some of which were actually reconstructed using the fanqie method or were inferred to be the same as their modern homophones.
Go-on readings were formerly referred to as Wa-on (和音?, lit. "Japanese sound"). The term 'go-on' was first introduced in the mid-Heian, likely by people who wished to promote kan-on readings. During the Tang dynasty, people in Chang'an referred to their own way of reading characters as qínyīn (秦音 shin'on?, lit. "Qin sound") and all other readings, particularly those originating south of the Yangtze, as wúyīn (呉音 go'on?, lit. "Wu sound") or one of many other similar names. It is thought that Japanese students studying in China adopted this practice, and, taking the position that the Chang'an-based manner of elocution were the correct ones, they also began to refer to the previously imported, unfashionable kanji readings as "go-on".
Go-on readings were also occasionally referred to as Tsushima-on (対馬音?) and Kudara-on (百済音?, literally "Baekje sound") because of a story that claims a Baekjean nun named Hōmei (法明?) had taught Buddhism in Tsushima by reading the Vimalakīrti Sutra entirely in go-on. Because of this, go-on has been dubbed "imitations of Korean imitations."
Go-on readings are generally less orderly than kan-on readings, but can be characterized as follows.
- Middle Chinese's voiced consonants were distinguished from unvoiced consonants when they occurred in syllable-initial positions.
- Syllable-initial nasal consonants of Middle Chinese are pronounced as nasals (m-, n-). In kan-on, they are interpreted as voiced plosives (b-, d-).
- In some characters, -o and -u are both acceptable and widespread, e.g., 素 (so, su), 奴 (no, nu) and 都 (to, tsu).
|character/word||Go-on (呉音)||Kan-on (漢音)|
Most of the content of this article comes from the equivalent Japanese-language article, accessed on June 5, 2006.