Toppan Inc., a printing company, is planning to release an AI smartphone app that could help decipher Japanese cursive and potentially billions of historical documents.

The app’s beta version is set for release later this month, while the full version is scheduled to become available to the public this March.

Historical documents and manuscripts are often written in kuzushiji, a form of Japanese cursive. This poses a hurdle to interpretation and usage, not only to researchers but also to other people who have old letters and diaries stored at home. Today, roughly 0.01% of Japan’s population can read cursive.

In the app, after taking a photograph of a section of a manuscript, a user can select “full-auto mode” which enables the AI to decipher several sentences at a time, separating cursive characters into their individual, contemporary forms. If a user is stuck on deciphering a specific character, by selecting “one-letter mode,” the app can provide multiple possible single-character suggestions that may assist, in addition to context clues from other sentences.

Toppan released an AI-based optical character recognition manuscript deciphering online service called Fuminoha Zemi in 2021, which is available for use by corporate entities and educational and research institutions. Since then, individuals reached out to the company to request that the service be made available to other users, prompting Toppan to start developing a smartphone app.

Now, the company hopes the service and smartphone app will help inform the public with new findings from eras past regarding scenes of daily life, how the country responded to natural disasters, and customs and more — not only for preservation, but as resources for regional tourism and revitalization as well.

“Toppan is a printing company, and so preservation and analysis of old manuscripts and documents is just one part of our work,” Toppan public relations representative Taiki Nishio said.

The app has been in experimental use by institutions including Mitsui Bunko archive, the Kyoto City Historical Museum and Wayo Women’s University since Sept. 2022. Toppan, alongside the National Institute of Japanese Literature and the National Institute for the Humanities, began research and development in deciphering cursive in 2015.