# Japanese License Plate Recognition: Heimdall Adds Japan-Spec Plates — Decoding Region Names, Class Numbers, and Vehicle Size

> HITech's license plate recognition now officially supports Japanese plates (ナンバープレート), reading all four fields — region name, classification number, hiragana, and serial number — and distinguishing regular cars from kei cars and private from commercial use by plate color and size, helping parking lots, residential complexes, and traffic-management sites in Japan adopt smart recognition.

Published: 2026-05-29
Canonical: https://www.hitech.com.tw/en/news/2026-05-29
Publisher: Heimdall Intelligent Technology (HITech) — https://www.hitech.com.tw

Heimdall Intelligent Technology continues to expand the country coverage of its license plate recognition engine and now officially supports Japanese license plate (ナンバープレート) recognition, reliably handling Japan-spec plates' multiple fields, mixed scripts (kanji, hiragana, digits), and varied background colors for parking, access-control, and traffic-analysis deployments in Japan.

Unlike Taiwanese plates, a Japanese plate is not a single number string but is composed of four meaningful fields:

(1) Region name (upper left): the location of the transport bureau or vehicle inspection registration office where the vehicle is registered — e.g., 品川 (Shinagawa), 練馬 (Nerima), 横浜 (Yokohama), なにわ (Naniwa). As regional "local" plate names (ご当地ナンバー) continue to be added, well over a hundred region names now exist, ranging from one to four characters and mixing kanji and hiragana.

(2) Classification number (upper right): a three-digit number whose leading digit denotes the vehicle category — leading 1 for ordinary truck, 2 for ordinary bus/large passenger (11+ seats), 3 for ordinary passenger car, 4 or 6 for small truck, 5 or 7 for small passenger car, 8 for special-purpose, 9 for large special vehicle, 0 for construction machinery.

(3) Hiragana (lower left): indicates the vehicle's use, drawn from a defined set of hiragana rather than a continuous range. Private vehicles use characters such as さ, す, せ, そ, た, ち…, excluding easily confused or specially meaningful characters such as お, し, へ, and ん; commercial vehicles use あ–こ and を; and rental cars always use わ or れ.

(4) Serial number (lower right): a four-digit number from 0001 to 9999 (9,999 combinations), where leading zeros are shown as dots (・), e.g., ・・・1 or ・123, and which can be chosen via the preferred-number system.

Beyond the field contents, plate color and size also reflect vehicle size and use: white with green text is a private ordinary car, green with white text is commercial (taxi, freight, etc.); yellow with black text is a private kei car (a light vehicle under 660cc), and black with yellow text is a commercial kei car. Plate size also varies by category — ordinary cars, kei cars, motorcycles, and large vehicles each differ. Our system infers vehicle type from a combination of background color, size, layout, and text information rather than relying on any single field, accommodating exceptions such as special-purpose and commemorative plates.

The challenge of Japanese plates lies in the large number of region names, the mix of kanji and hiragana, the wide variation in character size and layout, and the recognition difficulty caused by white, green, and yellow backgrounds and their reflective characteristics. With deep-learning models trained on the Japanese character set together with image preprocessing, we recognize each of these fields reliably across different lighting and angles.

Operators with parking, residential, or traffic-management needs in Japan are welcome to contact us — we will tailor a recognition solution to the local plate specifications and your site conditions.

## Media

- image: https://www.hitech.com.tw/images/example/japan-license-plate-1.webp