Japanese names: order, san/sama, and gender guessing
Japanese names put the family name first at home, but are often reordered to given-family on English business cards and email signatures to match Western convention, so the order alone will not tell you which part is which. This guide covers name order, the honorifics used in email, how far gender can be guessed from a given name, and a safe neutral form for when you are unsure.
Name order and structure
In Japanese, family name comes first: Yamada Hiroshi is Mr. Yamada, given name Hiroshi. On an English signature this is frequently flipped to "Hiroshi Yamada" to read naturally for Western correspondents, and business cards sometimes print both orders. If a name has three or more parts, or you cannot tell which is which, treat the last word before any comma as the more likely family name and check the email signature or company directory before committing to a title.
Japanese given names range from one to four syllables and are written with a mix of kanji, hiragana or katakana; the same sound can map to many different characters with different meanings, which is part of why gender guessing from a romanised name alone is imprecise.
Honorifics and titles in business email
The honorific -san attaches to the family name and is gender-neutral: Yamada-san works for a man or a woman and is the safest default when writing to a Japanese colleague in a mixed English/Japanese context. -sama is more formal and common in customer-facing letters ("Yamada-sama"). In English-language business email, "Dear Mr./Ms. Yamada" is standard once gender is confirmed; "Dear Yamada-san" or the full name with no title are both acceptable neutral fallbacks.
First-name-only address is unusual in Japanese business culture even after some familiarity; sticking to the family name plus honorific is the lower-risk default.
Gender and names
Some name endings correlate with gender in practice, without being rules: names ending in "-ko" or "-mi" (Yumiko, Naomi) lean female, names ending in "-o", "-shi" or "-ta" (Hiroshi, Kenji, Takashi) lean male, but there are common exceptions on both sides and the correlation weakens further once a name is only seen in Latin letters. Treat a single Japanese given name as a moderate-confidence guess at best, not a certainty.
What to write when unsure
When gender is unclear, "Dear [family name]-san," or the full name without a title reads correctly in both English and Japanese business register. Avoid committing to "Mr." or "Ms." from name-ending guesses alone in a first cold email; ask, or mirror the signature the person themselves uses once you have a reply.
Examples
Formal letter, gender known (male)
Dear Mr. Yamada,
Formal letter, gender known (female)
Dear Ms. Sato,
Formal letter, gender unclear
Dear Yamada-san,
Everyday email, first contact
Hi Hiroshi,
Names to try
Frequently asked questions
Is the family name first or last in a Japanese name?
First in Japanese order (Yamada Hiroshi), but English-language signatures and business cards often flip it to given-family to match Western convention.
What does -san mean and can I use it for anyone?
-san is a gender-neutral honorific attached to the family name, roughly equivalent to Mr./Ms. It is safe for almost any adult in a business context.
Can I guess gender from a Japanese given name?
Only loosely. Endings like -ko or -mi lean female and -o, -shi or -ta lean male, but exceptions are common enough that this is a guess, not a rule.
Is it rude to use someone's first name in a Japanese business email?
It can read as overly familiar. Family name plus -san, or "Mr./Ms. [family name]" in English, is the safer default until told otherwise.