Romanization Day

What Is Romanization Day?

Every May 20th is also "Romanization Day" (ローマ字の日, Rōmaji no Hi) in Japan. It was established in 1955 by the Nippon-no-Rômazi-Sya (日本のローマ字社), a foundation promoting the use of Roman letters for Japanese. The date is tied to physicist Aikitsu Tanakadate (田中舘愛橘), who devised the Nihon-shiki romanization system and championed romanization throughout his life. He died on May 21, 1952, and the round-numbered 20th was chosen for the commemoration.

Romanizing Japanese

The romanization of Japanese — writing the sounds of the Japanese language using the Latin alphabet — dates back to European missionaries in the late 16th century. Several competing systems have been developed: Hepburn romanization (ヘボン式, most widely used internationally), Nihon-shiki (日本式, devised by Tanakadate in 1885 based on the Japanese syllabary chart), and Kunrei-shiki (訓令式, adopted by cabinet order in 1937 based on Nihon-shiki and reissued in 1954). Each system makes different choices about how to represent Japanese sounds — for example, "し" is "shi" in Hepburn but "si" in Nihon-shiki and Kunrei-shiki.

Romanization in Japan's Global Context

Roman letters (ローマ字, rōmaji) play an important practical role in modern Japan — they appear on railway station signs (alongside Japanese), on passports, in product names marketed internationally, and in the input systems used to type Japanese on computers and smartphones. The question of which romanization system to use — and when — remains a practical issue in Japan's international communication.

The Romanization Debate

In the Meiji era, some reformers proposed writing Japanese entirely in Roman letters, arguing that the complex writing system was an obstacle to modernization. This proposal was never adopted, but the debate about romanization's role continues in milder forms: how to romanize station names, how to format Japanese names in international contexts, and how to balance tradition with international readability. Tanakadate's grave in his hometown in Iwate Prefecture is inscribed in Nihon-shiki romanization.

Fun Facts

• IME input: The most common way to type Japanese on computers and smartphones today is through romaji input (ローマ字入力, rōmaji nyūryoku) — users type the romanized pronunciation, and software converts it to hiragana and kanji. This makes romanization an everyday necessity for millions of users.
• Hepburn system: James Curtis Hepburn (1815–1911), the American missionary and physician who compiled the Japanese-English dictionary "Wa-Ei Gorin Shūsei" (1867), developed the romanization system that bears his name and remains the most internationally recognized standard.