It's not just "sushi" and "emoji" anymore. Today, roughly 600 Japanese words appear in English dictionaries, and in December 2025 eleven more joined the world's most authoritative English dictionary, among them "yokai," "senpai," and "mottainai." Beyond anime and manga, the Japanese language itself is becoming part of the global lexicon.

What is the Oxford English Dictionary?

The Oxford English Dictionary (OED), published by Oxford University Press, stands as the world's largest and most authoritative English dictionary. Since its first edition in 1928, it has documented the historical development of the English language and currently contains approximately 600,000 words.

What distinguishes the OED is its approach of recording not just definitions but also the earliest known usage of each word with citation examples. Japanese loanwords have been incorporated into English since 1577, starting with "kuge" (court noble). Today, approximately 600 words of Japanese origin appear in the dictionary.

The 11 Japanese Words Added in December 2025

The December 2025 update added the following eleven Japanese-origin words:

1. Yokai Supernatural beings from Japanese mythology and folklore. Global recognition increased dramatically through anime and manga series such as "Demon Slayer," "Jujutsu Kaisen," and "GeGeGe no Kitarō." The OED defines it as "various spirits or supernatural beings in Japanese mythology and folklore and in modern Japanese fiction, especially anime and manga."

2. Senpai A term for an older student or senior colleague. Unlike English equivalents such as "senior" or "mentor," senpai captures the distinctly Japanese hierarchical relationship dynamic. The internet meme "notice me, senpai" also contributed to its widespread recognition.

3. Mottainai An expression of regret over wastefulness. The OED explains it as conveying "regret or disapproval at rudeness or wastefulness, now especially significant in environmental discussions." The term gained international prominence when Kenyan environmental activist Wangari Maathai introduced it to global audiences.

4. Naginata A Japanese polearm featuring a curved blade on a long shaft. Historically associated with women of the warrior class, it continues today primarily as a martial art practiced mostly by women and girls.

5. Senbei Traditional Japanese rice crackers available in both sweet and savory varieties. These snacks have become popular among international tourists visiting Japan.

6. Ekiden A long-distance relay marathon first held in Japan in 1917. Events like the Hakone Ekiden have become synonymous with Japanese New Year traditions, and this unique sporting format has gained recognition in English-speaking countries.

7. White Day A Japanese custom where men reciprocate Valentine's Day gifts on March 14. Having spread across East and Southeast Asia, it demonstrates how Japanese cultural practices influence regions beyond the English-speaking world.

8. PechaKucha A presentation format born in Tokyo in 2003. Speakers present 20 slides at 20 seconds each, totaling 6 minutes and 40 seconds. This format has been adopted in business and creative communities worldwide.

9. Love hotel Short-stay accommodation designed for couples. Representing an iconic aspect of Japanese urban culture, these establishments have attracted attention from international travelers and media.

10. Washlet The brand name for TOTO's heated toilet seat with bidet functions, launched around 1980. Symbolizing Japanese innovation in bathroom technology, it has amazed international visitors and earned a place in the OED as a proper noun.

11. Waifu A term from otaku culture referring to a fictional female character regarded as an ideal romantic partner. Originating from the anime "Azumanga Daioh" (2002), where the phrase "mai waifu" (my wife) captured international fans' attention, it evolved into an English word with its own distinct meaning.

Why Japanese Language Influence Is Accelerating

Several factors explain why Japanese-origin words continue entering the OED.

First, anime and manga have achieved global reach. Streaming platforms like Netflix and Crunchyroll deliver Japanese content instantly worldwide. The addition of "yokai," "senpai," and "waifu" directly reflects this pop culture influence.

Second, international tourism to Japan has surged. Before the pandemic, approximately 32 million people visited Japan in 2019, with 2024 setting new records. Words like "senbei" and "Washlet" entered the dictionary because more foreigners have experienced Japanese daily life firsthand.

Third, Japanese concepts have entered global discourse. "Mottainai" features in environmental discussions, while "PechaKucha" has become standard in business communication, both representing untranslatable concepts that have permeated international society.

Looking Ahead

Japanese additions to the OED will likely continue. The March 2024 update added 23 words including "isekai" (parallel fantasy world), "kintsugi" (golden joinery repair), and "mangaka" (manga artist), demonstrating the expanding influence of Japanese language.

However, linguists note that Japanese words absorbed into English sometimes shift in meaning or nuance. For example, "waifu" carries a different meaning from the Japanese "ワイフ" (wife), and "omiyage" in English refers only to gifts for others, excluding souvenirs purchased for oneself, which the Japanese term includes.

Language internationalization inevitably brings cultural exchange and transformation. As Japanese becomes part of the world's "common vocabulary," how we embrace these changes becomes a question for Japanese people ourselves.

What Japanese words are commonly used in your country? And conversely, are there words from your language that have been adopted in Japan? We'd love to hear your experiences!

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