It's surprisingly little known, but the text AI learned from is overwhelmingly English. Information on the internet is roughly half or more English, while Japanese is only a few percent. Whether or not you know this bias changes the quality you can draw out.
For Global Topics, "Making It Think in English" Is Powerful
For the latest overseas technology, universal academic subjects, and specialized themes, AI's knowledge is often deeper in English. That's where the following trick comes in handy.
Think in English, but write the answer in Japanese.
Have the substance processed in knowledge-rich English, and only the output rendered in Japanese. This alone can sometimes make answers on global subjects one notch deeper. You don't even need to be able to read English.
For Japan-Specific Matters, Japanese Has the Advantage
Conversely, for uniquely Japanese topics—such as Japan's systems, laws, domestic services, trends, dialects, and honorific language—asking in Japanese is more accurate. Use them according to the subject.
- Technology from overseas / universal knowledge → "Think in English, answer in Japanese"
- Domestic Japanese matters / Japanese expression itself → just use Japanese normally
A Bit of Trivia: Japanese Is Costly
AI processes text in units called "tokens." Japanese uses 1–2 tokens per character, making it pricier than English. In paid use that handles large volumes of long text, there are situations where communicating in English is faster and cheaper. You don't need to worry about it in everyday use, but keeping "Japanese is internally heavy" in the back of your mind makes it click why long passages feel sluggish.
Tips When Having It Write Japanese Text
- Paste a model — Showing a sample of the writing style you like stabilizes the honorifics and tone
- Specify the reader — "For executives" or "for homemakers" changes the word choice
- Have it fix anything unnatural — "This reads like a translation. Make it more natural Japanese" sets it right
Summary
Use an English mind for world topics, and Japanese for Japan topics.
Simply knowing the "behind-the-scenes" fact of this language bias lets you draw better answers from the very same AI.