How to Identify Japanese Coins
Most Japanese coins can be identified in minutes once you know what to look for. This guide walks through the diagnostics collectors actually use — inscriptions, dates, metal, measurements and references — and shows how to confirm what you find with a single photo.
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. AI Coin Collector shows the Numista catalogue price per grade, a quick reference before you compare recent sold results.
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.
Identify Japanese coins from a photo with AI Coin Collector
The fastest way to identify a Japanese coin is to photograph it with AI Coin Collector. The app uses our own AI vision model to suggest the type, estimates its condition on the Sheldon 1–70 scale, and shows the Numista catalogue price per grade.
From there, AI Coin Collector works as a full collection manager: organize and filter your sets, share finds with the community, earn XP and achievements, and take on challenges. The app is free to start, without ads or tracking, with a Premium subscription on top.
Frequently asked questions
How do I identify Japanese coins?
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. Working through checks like these in order narrows down most pieces quickly — and a clear photo in AI Coin Collector turns the whole process into a few seconds.
What Western year is Shōwa 55?
Add the Shōwa offset of 1925: Shōwa 55 is 1980. The same method works for every era — Meiji year + 1867, Taishō + 1911, Heisei + 1988, Reiwa + 2018. If the date reads 元年 (gannen), it is year one of that era.
Are Japanese coins worth anything?
Common modern issues are worth little, but Meiji-era silver yen typically bring $100–400, early gold much more, and scarce sen varieties real premiums. Kanei Tsuho mon coins are cheap and plentiful, with exceptions for rare castings.
Can an app identify Japanese coins from a photo?
Yes. AI Coin Collector identifies coins, tokens and medals from a single photo using our own AI vision model, estimates condition on the Sheldon 1–70 scale, and shows the Numista catalogue price per grade.