Mikey Does

How Japan Borrowed China’s Writing System — and Spent 1,500 Years Making It Its Own

Japanese learners hit the on’yomi and kun’yomi problem early. Why does 明 read as myō, mei, aka, akaru, akeru, and ake? Why does a single character carry both a Chinese-sounding reading and a native Japanese one? The answer is historical: Japan absorbed Chinese writing in multiple waves over several centuries, each wave leaving its own layer of pronunciation behind. The Tang Dynasty was the crucial midpoint in that process — the moment Japan went from cautiously borrowing characters to systematically restructuring its government, religion, and writing around a Chinese model. But the story starts before Tang, and the divergence continued long after.

What Learners Notice

A recurring complaint on r/LearnJapanese — appearing in dozens of threads over the years — is that kanji readings feel arbitrary. Learners memorize one reading only to encounter a second, then a third, with no apparent logic for when each applies. A common thread asks something like: “If I already know Chinese characters, can I just read Japanese?” The community answer is nuanced: you’ll recognize many characters and some meanings will transfer, but the readings won’t, the grammar is entirely different, and — unexpectedly — some characters mean something different or even the opposite in Japanese.

Chinese-speaking learners sometimes discover these discrepancies with amusement. 手紙 (tegami) is “letter” in Japanese; in Mandarin (shǒuzhǐ) it means toilet paper. 大丈夫 (daijōbu), meaning “it’s okay” or “are you alright?” in Japanese, means “a grown man” in classical Chinese and closer to “capable man” in modern Mandarin. These are not translation errors — they are the result of fifteen centuries of independent semantic evolution after the initial borrowing.

Before the Tang: How Characters First Reached Japan

Japan had a spoken language but no writing system of its own. The Chinese writing system was already centuries old — developed over the Shang and Zhou dynasties — by the time it began reaching the Japanese archipelago. The transmission route was the Korean peninsula.

The traditional account, recorded in the Kojiki (712 CE) and Nihon Shoki (720 CE), attributes the arrival of Chinese characters to a scholar from the Korean kingdom of Baekje named Wani (王仁), who supposedly brought the Confucian Analects and the Thousand Character Classic to the Japanese court sometime in the late 4th or early 5th century. Historians treat Wani as a semi-legendary figure — the event may be composite or compressed — but the broader picture is well-supported: Chinese script entered Japan through direct contact with the Korean kingdoms of Baekje, Goguryeo, and Silla, who were themselves deeply Sinicized and served as cultural intermediaries.

The readings absorbed during this earliest phase are called Go-on (呉音) — named after the Wu region of eastern China, reflecting the linguistic layer of Chinese spoken in that region and transmitted through the Korean kingdoms. Go-on readings survive today in Buddhist terminology and classical compounds. The reading myō in 明 is Go-on.

The Tang Dynasty: When Japan Went All In

The pivotal shift came with Japan’s systematic engagement with Tang China (618–907 CE). Beginning in 630 CE, the Japanese court began dispatching formal diplomatic missions to the Tang capital at Chang’an — the kentoshi (遣唐使), or “emissaries to Tang China.” These missions, which continued until 894 CE when Sugawara no Michizane recommended their suspension, were not just diplomatic formalities. They were structured knowledge-transfer operations.

Scholars, Buddhist monks, and students traveled to Chang’an for years at a time, studying Tang administrative law, Buddhism, medicine, astronomy, poetry, and calligraphy. They returned to Japan carrying texts, knowledge, and the pronunciation of Tang Chinese — a prestige dialect that the Japanese court adopted as the standard for formal reading. This layer of readings is called Kan-on (漢音), from Kan (漢), referring to China. The reading mei in 明 is Kan-on.

The Nara period (710–794 CE) was the peak of Tang-inspired Sinicization. Japan built a new capital at Nara (Heijō-kyō) modeled directly on Chang’an’s grid plan. The legal codes (ritsuryō) were adapted from Tang governance models. Buddhist texts were copied in quantity. Official correspondence was conducted in classical Chinese (kanbun). The Nara court was, in terms of its written culture, operating largely within a Chinese frame.

A third wave followed centuries later. Zen Buddhism’s spread from Song and Ming Dynasty China introduced another set of readings, Tō-on (唐音), concentrated in Zen temple vocabulary and certain everyday terms. The word futon (布団) carries a Tō-on reading.

One character, three historical layers of Chinese pronunciation — each preserved because none fully replaced the others.

How Japan Made the Borrowed System Its Own

The Man’yōgana system, visible in the 8th-century poetry anthology Man’yōshū (compiled around 759 CE), shows the adaptation process already underway. Japanese scribes were using Chinese characters not for their meanings but purely for their phonetic values — writing native Japanese poetry by borrowing the sounds of Chinese characters. The character 安 (an in Chinese) was used to represent the Japanese syllable a; 以 (yi) for i. This was kanji being repurposed into a phonetic syllabary.

By the early Heian period (794–1185 CE), this phonetic use had produced two new scripts. Hiragana evolved from the cursive simplification of Man’yōgana characters — the character 安 became あ, 以 became い. Katakana developed in parallel, from abbreviated portions of kanji used by Buddhist monks as marginal reading aids in texts. Together, hiragana and katakana gave Japanese writers a way to represent any Japanese sound without relying on the Chinese semantic content of characters at all.

Japan also invented entirely new characters with no Chinese counterpart, called kokuji (国字, “national characters”). These are characters created in Japan for Japanese words that had no equivalent in the Chinese vocabulary:

  • 働く (hataraku, to work)
  • 峠 (tōge, mountain pass)
  • 畑 (hatake, dry field)
  • 辻 (tsuji, street crossing)

Kokuji have no Go-on or Kan-on reading because they were never Chinese — they have kun’yomi only, and occasionally a fabricated on’yomi assigned later. They are a small category, but their existence is a clear sign that the borrowed system was being adapted to Japanese reality, not just applied wholesale.

The Postwar Simplification and the Three-Way Divergence

By the 20th century, the writing systems of Japan and China were already somewhat distinct. After World War II, they diverged further in different directions.

Japan’s Ministry of Education published the Tōyō Kanji list in 1946 — 1,850 characters recommended for general use, with a number of official simplifications to individual character forms. This was revised upward to the Jōyō Kanji list of 1,945 characters in 1981, and expanded again in 2010 to the current 2,136 characters that form the standard for education, government documents, and media.

The People’s Republic of China introduced its own Simplified Chinese character reforms in the 1950s and 1960s, reducing stroke counts substantially in a different set of characters and by different methods. Taiwan and Hong Kong maintained Traditional Chinese.

The result is a three-way split: modern Japanese kanji is neither Simplified Chinese nor Traditional Chinese. Some characters are identical across all three systems; some are simplified the same way; many are simplified differently or not at all in one system while simplified in another. A character that looks familiar to a Traditional Chinese reader may have a slightly different form in Japan; one that a Simplified Chinese reader recognizes may be unrecognizable in Japan.

What This Means for Japanese Learners

The history resolves several learner confusions. Multiple on’yomi for the same character are not arbitrary — they are historical strata. Go-on readings tend to appear in Buddhist vocabulary and set expressions; Kan-on readings are more common in formal compounds; Tō-on readings are concentrated in specific domains like Zen and certain food terms. Recognizing which layer a reading comes from doesn’t require fluency in historical linguistics, but knowing the layers exist removes the sense that the system is random.

Semantic drift is real and should be expected. Japanese absorbed Chinese characters over a long period when both languages were evolving; the meanings that attached to characters in Japan followed Japanese semantic development, not Chinese. Learners with Chinese background have a genuine advantage in recognizing character forms and some compound meanings, but they should not expect meanings to transfer reliably.

Kokuji are a small, learnable category. Most major dictionaries flag them. Because they have no on’yomi (or a pseudo-on’yomi), they’re actually straightforward: there’s only one reading to learn.

The Jōyō Kanji list is not an ancient canon — it’s a mid-20th century administrative standard, revised three times. Characters on the list were chosen for their frequency in modern Japanese public life, not for their historical prestige. This means the “standard” kanji a learner studies is itself a modern selection from a much larger historical inventory.

Learners using Sakubo — a Japanese learning app built around this kind of layered vocabulary knowledge — encounter the on’yomi/kun’yomi structure as organized by frequency and context, which reflects how the characters actually function in modern usage rather than as abstract historical categories.

Social Media Sentiment

The Tang Dynasty–kanji history angle is rarely discussed in learner communities outside of dedicated threads — most conversation stays at the practical level of “how do I memorize readings?” A 2023 thread on r/LearnJapanese titled something like “Why does every kanji have five different readings?” attracted hundreds of responses, with the top answers explaining Go-on/Kan-on as historical layers; the responses were consistently upvoted as genuinely useful context rather than just trivia. The Chinese-speaker-learning-Japanese experience is a recurring topic, with the dominant community view being “it helps with recognition, hurts with pronunciation, and produces confusion on meanings.” The semantic drift examples — 手紙, 大丈夫, 勉強 — tend to appear as amusing illustrations rather than serious complaints.

Last updated: 2026-06

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