Keicho Ichibuban Die Study

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In mid-2024, I began an in-depth die study of Keicho ichibuban in hopes of understanding them better. Well over a year later, the paper is complete, and I believe this research has uncovered a more comprehensive way to divide Keicho ichibuban. It has also revealed some unexpected rarities, and - I believe - clues about the purpose of Double Hon Keicho ichibuban.

The paper is available below in both English and Japanese (in the same file). Refer to the table of contents to jump to your preferred language. It assumes a general familiarity with the design elements of ichibuban but provides most other relevant background information, so it should be accessible to most collectors of the series. (If you have any questions about design elements, some of them may be answered here.)

This paper was first released in November 2025, and any updates can be found on this page going forward. At this point, there have been no further updates or discoveries.

I welcome any and all feedback. The entire goal of this die study is to begin a conversation with other researchers and collectors and provide a basis for further research.

Please download the PDF below for the full die study.