Keicho Ichibu Die Study

In mid-2024, I began an in-depth die study of Keicho ichibu 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 ichibu. It has also revealed some unexpected rarities, and - I believe - clues about the purpose of Double Hon Keicho ichibu.

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 gold ichibu 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.

Eight Major Types

Refer to pages 40-43 (6-9 for Japanese) in the PDF above for criteria to attribute calligraphy style (K, S, E, H, U, or Y) and time period (Early, Intermediate, or Late).

Single Hon pieces have a character in the top right corner of side A; Double Hon pieces have the same character in both top corners of side A.

Minor types are discussed in more detail on pages 54-57 (20-23 for Japanese), but all three are very rare.

Keicho Ichibu Die Study

Eight Major Types

Early No Hon K

Intermediate No Hon K

Intermediate Single Hon K

Intermediate No Hon S

Intermediate Single Hon S

Intermediate Double Hon S

Late No Hon E

Late Single Hon E

Late Single Hon E

Three Minor Types

Late No Hon H

Late No Hon U

??? No Hon Y

??? No Hon Y