What counts as Japanese coins?
Japanese coinage splits at the Meiji Restoration. Before it, Japan cast square-holed mon coins — above all the Kanei Tsuho (寛永通寶), produced for over two centuries from 1626 — plus oval gold and silver trade pieces. From 1870, the modern mint at Osaka struck Western-style yen, sen and rin, and every coin since carries a date in the Japanese era system rather than a Western year.
That era system is the key identification skill: a coin is dated by the reigning emperor’s era name plus a year number, so reading and converting the era is how you date any modern Japanese coin.
Step-by-step: identifying Japanese coins
Work through these checks in order. Each one eliminates possibilities, and together they identify the large majority of Japanese coins without any special equipment:
- Find the era name in kanji: 明治 (Meiji), 大正 (Taishō), 昭和 (Shōwa), 平成 (Heisei) or 令和 (Reiwa).
- Read the era year — the numeral next to the character 年 (year) — and note that legends on Meiji through early Shōwa coins often read right to left.
- Convert to a Western date by adding the era offset: Meiji + 1867, Taishō + 1911, Shōwa + 1925, Heisei + 1988, Reiwa + 2018 — so Shōwa 40 is 1965.
- Know the special first year: 元年 (gannen) means “year one” of an era rather than a numeral.
- For square-holed pieces, identify Kanei Tsuho mon coins by their four characters; reverse marks, size and calligraphy separate the many issues cast between 1626 and the 1860s.
- Weigh the silver: a Meiji silver yen should weigh 26.96 g — a critical check, since Japanese trade dollars and yen are heavily counterfeited.
Are Japanese coins valuable?
Everyday 20th-century Japanese coins are plentiful and cheap, but the Meiji era is a strong market: genuine silver yen commonly bring $100–400 and more in high grade, early gold is far dearer, and key dates in the sen series carry solid premiums. Cast mon coins are abundant at $2–10, with scarce varieties prized by specialists.
As always in numismatics, condition is king and rarity is queen. Before settling on a value, check what comparable pieces actually sold for recently; asking prices and dated guidebooks both mislead. CoinVault Pro surfaces real eBay sold prices alongside Numista catalog data so you can read the current market at a glance.
Common pitfalls and fakes
Experienced collectors get burned less often because they check for these problems first:
- Reading the era year in the wrong direction on right-to-left legends and misdating the coin by decades.
- Counterfeit Meiji silver yen and trade dollars are extremely common — verify the 26.96 g weight and struck surfaces.
- Confusing Japanese cast mon with Chinese cash: the reign-title formats and calligraphy differ.
- Assuming a big, impressive Meiji coin is rare: many dates are common in worn grades and only scarce in high grade.
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