山形県 (Yamagata)
Flag
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Flag
Not available
Prefecture
Yamagata (山形県, Yamagata-ken) flies a bright blue flag bearing three white angular peaks — adopted in 1963 after a public design competition — and a related prefectural emblem of the same triangular mountain motif, formally adopted in 1976 to mark a century of prefectural government. Both designs evoke the prefecture’s mountains and the Mogami River, not any feudal clan crest, despite an occasionally repeated claim linking the emblem to the katabami (wood sorrel) mon of the historic Mogami clan.
| Prefecture | Yamagata (山形県, Yamagata-ken) |
|---|---|
| Type | Ken (県) — ordinary prefecture |
| Region | Tōhoku |
| Capital | Yamagata City (山形市) — itself a distinct municipality with its own separate city emblem |
| Established | Modern boundaries fixed 21 August 1876, merging Yamagata, Okitama and Tsuruoka (Sakata) prefectures; roots trace to the 1871 haihan-chiken abolition of domains |
| Flag | Three white angular peaks on bright blue; adopted 26 March 1963; field colour changed from dark blue-green to bright blue, 16 April 1971 |
| Emblem (kensho) | Same triangular mountain motif, colour-neutral; adopted 21 August 1976 |
| Official flower | Safflower (beni-bana), designated 31 March 1982 |
| Official tree | Cherry, designated 31 March 1982 |
| Official bird | Mandarin duck, designated 31 March 1982 |
Flag of Yamagata Prefecture — Bright blue field, three white angular mountain peaks, adopted 1963
The flag of Yamagata Prefecture is a bright blue field bearing three white angular peaks, arranged like a stylised “∧∧∧”. The Yamagata Prefectural Government describes the triangular forms as representing the prefecture’s mountains — including Mount Chōkai and Mount Gassan — while simultaneously evoking the flow of the Mogami River (最上川), the major waterway that runs the length of the prefecture and carries deep cultural significance for its residents. The white cut-out is said to recall snow on mountains such as Mount Zaō, whose famous juhyō (“ice trees”, rime-covered conifers) are a well-known regional symbol; officially, the white is described as expressing the honest, unpretentious character of the prefecture’s people, while the sharp angles signal aspirations for continued development. The separate prefectural emblem (県章, kensho) reuses this same three-peak design, without a fixed official colour, described simply as conveying “composed dignity.”
26 March 1963 (Shōwa 38) — the flag. Following a public competition launched in December 1962 that drew 332 entrants and 486 submitted designs, an entry by Shōji Shigeru was selected by the February 1963 review panel, and the flag was formally adopted the following month.
16 April 1971 — a colour change. The flag’s background, originally a dark blue-green chosen as a complementary colour to the red disc of the national flag when flown alongside it, was changed by prefectural announcement to the brighter blue used today.
21 August 1976 (Shōwa 51) — the emblem. To mark the prefecture’s centennial, the government adopted a distinct emblem (kensho) carrying the flag’s mountain motif, intended to foster civic pride and support the prefecture’s continued development.
Some general sources on Japanese heraldry state that Yamagata’s emblem “adopts the katabami (wood sorrel) of the local feudal Mogami clan.” Independent research for this article did not confirm that claim. The Mogami clan, a branch of the Ashikaga lineage who ruled the Yamagata domain through the Sengoku and early Edo periods (most famously under Mogami Yoshiaki), are documented as having used crests such as the maruni futatsu-biki (two bars in a circle), a bamboo-and-sparrow design, paulownia, and a sixteen-petal chrysanthemum — not katabami. Katabami crests do appear in the prefecture’s heraldic history, but in connection with the Sakai clan, who ruled the Shōnai domain in the northwest of present-day Yamagata, not the Mogami. The official prefectural flag and emblem, for their part, were both selected through modern public design competitions in 1963 and 1976 and are explicitly described by the prefectural government as representing mountains and the Mogami River — a name that appears to be the likely source of confusion with the Mogami clan. Readers should treat any katabami/Mogami-clan attribution for the modern prefectural emblem with caution absent a citable official source.
A bright blue field with three white angular peaks, representing the prefecture’s mountains and the flow of the Mogami River. The white is said to evoke snow on peaks like Mount Zaō, reflecting the honest character of the prefecture’s people.
No confirmed link exists. The historic Mogami clan is documented as using crests such as the maruni futatsu-biki and bamboo-and-sparrow designs, not katabami — that wood-sorrel mon is instead associated with the Sakai clan of Shōnai. The modern flag and emblem were both chosen by public competition and officially represent mountains and the Mogami River, likely the source of the confusion with the similarly-named clan.
The flag was adopted 26 March 1963 after a public design competition, with its field colour brightened on 16 April 1971. The related prefectural emblem was adopted separately on 21 August 1976, marking the centennial of prefectural government.
The safflower (beni-bana), tied to the prefecture’s historic dye trade; the cherry tree; and the mandarin duck — all designated on 31 March 1982.
Last reviewed by the Emblema Mundi editorial team on 2026-07-04.