diff --git a/app/components/CharCells.vue b/app/components/CharCells.vue
index fec26ca..d0f791b 100644
--- a/app/components/CharCells.vue
+++ b/app/components/CharCells.vue
@@ -19,7 +19,7 @@ const { t } = useT()
 const { regions, regionIndices, tracks, showOld } = useColumnVisibility()
 
 // Read over the columns on show: with Japan hidden, a row that ran
-// CN | HK+TW | JP has two runs, not three with a gap where Japan was.
+// CN | JP | HK+TW has two runs, not three with a gap where Japan was.
 const signature = computed(() =>
   projectSignature(
     props.dimension === 'glyph' ? props.row.glyph : props.row.cp,
diff --git a/app/components/OverprintChar.vue b/app/components/OverprintChar.vue
index cbe5a38..6ae8b9d 100644
--- a/app/components/OverprintChar.vue
+++ b/app/components/OverprintChar.vue
@@ -3,9 +3,9 @@ import {
   fontRegionOf,
   glyphSignature,
   projectSignature,
+  signatureIndexOf,
 } from '~~/shared/row.ts'
 import {
-  COLUMNS,
   REGIONS,
   type CharRow,
   type Column,
@@ -57,7 +57,7 @@ const basis = computed(() =>
 const groups = computed(() =>
   projectSignature(
     glyphSignature(props.row),
-    basis.value.map((column) => COLUMNS.indexOf(column)),
+    basis.value.map(signatureIndexOf),
   ),
 )
 
diff --git a/app/composables/chars.ts b/app/composables/chars.ts
index 0b3db67..cce4ec7 100644
--- a/app/composables/chars.ts
+++ b/app/composables/chars.ts
@@ -86,7 +86,7 @@ const charIndex = ((): Map<string, number[]> => {
 /**
  * A row's partition signature under the chosen comparison dimension, read over
  * the columns on show. Hiding a column repartitions what is left, so a row
- * whose shown regions ran CN | HK+TW | JP becomes a two-form row once Japan is
+ * whose shown regions ran CN | JP | HK+TW becomes a two-form row once Japan is
  * out -- and lands under the chip that says so.
  */
 export const signatureOf = (
diff --git a/app/composables/prefs.ts b/app/composables/prefs.ts
index 9d5218f..f9f9d8f 100644
--- a/app/composables/prefs.ts
+++ b/app/composables/prefs.ts
@@ -66,12 +66,14 @@ export function useColumnVisibility() {
       : chosen
   })
 
-  /** Columns on show, in CN-HK-TW-JP-KR-old order. */
+  /** Columns on show, in CN-JP-old-HK-TW-KR display order. */
   const columns = computed(() =>
     COLUMNS.filter((column) => !off.value.has(column)),
   )
   const regions = computed(() =>
-    REGIONS.filter((region) => !off.value.has(region)),
+    COLUMNS.filter(
+      (column): column is Region => column !== 'old' && !off.value.has(column),
+    ),
   )
   /** The same regions as indices into REGIONS, which is how tuples are read. */
   const regionIndices = computed(() =>
diff --git a/app/locales/ja-jp.ts b/app/locales/ja-jp.ts
index 348e2e2..e95953d 100644
--- a/app/locales/ja-jp.ts
+++ b/app/locales/ja-jp.ts
@@ -32,7 +32,7 @@ export const jaJP: typeof zhCN = {
     title: '表示設定',
     language: '表示言語',
     emoji: '地域を旗で表示',
-    emojiHint: '「中・港・台・日・韓」を対応する旗の記号に置き換えます。',
+    emojiHint: '「中・日・港・台・韓」を対応する旗の記号に置き換えます。',
     outline: '重ね表示で輪郭線を使う',
     outlineHint:
       '重ねた字形を輪郭線で表示します。画が一つに潰れにくくなり、違いが分かりやすくなります。',
diff --git a/app/locales/ko-kr.ts b/app/locales/ko-kr.ts
index 244cb59..1fd1e7e 100644
--- a/app/locales/ko-kr.ts
+++ b/app/locales/ko-kr.ts
@@ -32,7 +32,7 @@ export const koKR: typeof zhCN = {
     title: '표시 설정',
     language: '인터페이스 언어',
     emoji: '지역을 국기로 표시',
-    emojiHint: '‘중·홍·대·일·한’ 표기를 해당 국기 기호로 바꿉니다.',
+    emojiHint: '‘중·일·홍·대·한’ 표기를 해당 국기 기호로 바꿉니다.',
     outline: '겹쳐 보기에서 윤곽선 사용',
     outlineHint:
       '겹친 자형을 윤곽선으로 표시해 획이 한 덩어리로 뭉치지 않고 차이가 더 잘 보이게 합니다.',
diff --git a/app/locales/zh-cn.ts b/app/locales/zh-cn.ts
index c866574..69b0b18 100644
--- a/app/locales/zh-cn.ts
+++ b/app/locales/zh-cn.ts
@@ -30,7 +30,7 @@ export const zhCN = {
     title: '显示选项',
     language: '界面语言',
     emoji: '用旗帜显示地区',
-    emojiHint: '把「中港台日韩」换成对应的旗帜符号。',
+    emojiHint: '把「中日港台韩」换成对应的旗帜符号。',
     outline: '叠印用空心字',
     outlineHint: '把叠在一起的字形改成描边，笔画不再糊成一团，分歧处更清楚。',
     columns: '参与对照的字形',
diff --git a/app/locales/zh-hk.ts b/app/locales/zh-hk.ts
index 5d0fa5e..199e954 100644
--- a/app/locales/zh-hk.ts
+++ b/app/locales/zh-hk.ts
@@ -32,7 +32,7 @@ export const zhHK: typeof zhCN = {
     title: '顯示選項',
     language: '介面語言',
     emoji: '用旗幟顯示地區',
-    emojiHint: '把「中港台日韓」換成對應的旗幟符號。',
+    emojiHint: '把「中日港台韓」換成對應的旗幟符號。',
     outline: '疊印用空心字',
     outlineHint: '把疊在一起的字形改成描邊，筆畫不再糊成一團，分歧處更清楚。',
     columns: '參與對照的字形',
diff --git a/app/locales/zh-tw.ts b/app/locales/zh-tw.ts
index 91a5284..f94b4be 100644
--- a/app/locales/zh-tw.ts
+++ b/app/locales/zh-tw.ts
@@ -32,7 +32,7 @@ export const zhTW: typeof zhCN = {
     title: '顯示選項',
     language: '介面語言',
     emoji: '用旗幟顯示地區',
-    emojiHint: '把「中港臺日韓」換成對應的旗幟符號。',
+    emojiHint: '把「中日港臺韓」換成對應的旗幟符號。',
     outline: '疊印用空心字',
     outlineHint: '把疊在一起的字形改成描邊，筆畫不再糊成一團，分歧處更清楚。',
     columns: '參與對照的字形',
diff --git a/app/pages/char/[key].vue b/app/pages/char/[key].vue
index 347c2d7..036da48 100644
--- a/app/pages/char/[key].vue
+++ b/app/pages/char/[key].vue
@@ -4,8 +4,9 @@ import {
   fontRegionOf,
   glyphSignature,
   projectSignature,
+  signatureIndexOf,
 } from '~~/shared/row.ts'
-import { COLUMNS, REGIONS, type Column } from '~~/shared/types.ts'
+import { REGIONS, type Column } from '~~/shared/types.ts'
 import {
   charPath,
   morphName,
@@ -100,7 +101,7 @@ const backTo = computed(() => listPlace.value?.fullPath ?? '/')
 const groups = computed(() =>
   projectSignature(
     glyphSignature(row.value!),
-    columns.value.map((column) => COLUMNS.indexOf(column)),
+    columns.value.map(signatureIndexOf),
   ),
 )
 
diff --git a/scripts/tests/columns.test.ts b/scripts/tests/columns.test.ts
index 1a3d28c..803d7b8 100644
--- a/scripts/tests/columns.test.ts
+++ b/scripts/tests/columns.test.ts
@@ -6,6 +6,7 @@ import { listingOptionsFor } from '../../shared/listings.ts'
 import {
   glyphSignature,
   projectSignature,
+  signatureIndexOf,
   varietyOf,
 } from '../../shared/row.ts'
 import {
@@ -38,6 +39,19 @@ const without = (...hidden: Region[]) =>
 const ALL_COLUMNS = [...REGIONS].map((region) => REGIONS.indexOf(region))
 const DEFAULT_COLUMNS = without('kr')
 
+describe('column ordering', () => {
+  it('shows mainland, Japan, old Japan, Hong Kong, Taiwan, then Korea', () => {
+    expect(COLUMNS).toEqual(['cn', 'jp', 'old', 'hk', 'tw', 'kr'])
+    expect(COLUMNS.map(signatureIndexOf)).toEqual([0, 3, 5, 1, 2, 4])
+    expect(
+      projectSignature(
+        glyphSignature(row('國')),
+        COLUMNS.map(signatureIndexOf),
+      ),
+    ).toBe('001111')
+  })
+})
+
 describe('reading a partition over the columns on show', () => {
   it('leaves a full row exactly as the data ships it', () => {
     for (const key of ['返', '骨', '海', '的'])
@@ -71,8 +85,7 @@ describe('reading a partition over the columns on show', () => {
     // 國: the mainland and Japan write 国, Hong Kong and Taiwan write 國 --
     // and so does the Japanese old form.
     expect(glyphSignature(row('國'))).toBe('011011')
-    const columns = (...keep: Column[]) =>
-      keep.map((column) => COLUMNS.indexOf(column))
+    const columns = (...keep: Column[]) => keep.map(signatureIndexOf)
     expect(
       projectSignature(glyphSignature(row('國')), columns('hk', 'tw', 'old')),
     ).toBe('000')
diff --git a/shared/listings.ts b/shared/listings.ts
index 1c60c6e..c0f2cad 100644
--- a/shared/listings.ts
+++ b/shared/listings.ts
@@ -14,13 +14,13 @@ export const LISTING_OPTIONS: readonly ListingOption[] = [
   { id: 'cn1', kind: 'tier', region: 'cn', tier: 1 },
   { id: 'cn2', kind: 'tier', region: 'cn', tier: 2 },
   { id: 'cn3', kind: 'tier', region: 'cn', tier: 3 },
+  { id: 'jp1', kind: 'tier', region: 'jp', tier: 1 },
+  { id: 'jp2', kind: 'tier', region: 'jp', tier: 2 },
+  { id: 'old', kind: 'old', region: 'jp' },
   { id: 'hk1', kind: 'tier', region: 'hk', tier: 1 },
   { id: 'tw1', kind: 'tier', region: 'tw', tier: 1 },
   { id: 'tw2', kind: 'tier', region: 'tw', tier: 2 },
-  { id: 'jp1', kind: 'tier', region: 'jp', tier: 1 },
-  { id: 'jp2', kind: 'tier', region: 'jp', tier: 2 },
   { id: 'kr1', kind: 'tier', region: 'kr', tier: 1 },
-  { id: 'old', kind: 'old', region: 'jp' },
 ]
 
 /**
diff --git a/shared/row.ts b/shared/row.ts
index ec3763e..fe9dea4 100644
--- a/shared/row.ts
+++ b/shared/row.ts
@@ -1,4 +1,4 @@
-import { REGIONS, type CharRow, type Region } from './types.ts'
+import { REGIONS, type CharRow, type Column, type Region } from './types.ts'
 
 /**
  * Which region's font should render this cell: the earliest region in its
@@ -66,6 +66,11 @@ export function glyphSignature(row: CharRow): string {
   return row.old ? row.glyph + row.old.glyph : row.glyph
 }
 
+/** Position of a displayed column in glyphSignature's stored-region order. */
+export function signatureIndexOf(column: Column): number {
+  return column === 'old' ? REGIONS.length : REGIONS.indexOf(column)
+}
+
 /**
  * A signature restricted to the columns on show, renumbered so groups are
  * named by first appearance among them.
diff --git a/shared/types.ts b/shared/types.ts
index 5fc366f..10a465a 100644
--- a/shared/types.ts
+++ b/shared/types.ts
@@ -1,5 +1,5 @@
-/** The five regions, fixed in CN-HK-TW-JP-KR order: column position carries
- * regional identity, color carries only grouping. */
+/** The five regions in stored tuple order. Column position carries regional
+ * identity in generated data; display order is defined separately below. */
 export const REGIONS = ['cn', 'hk', 'tw', 'jp', 'kr'] as const
 export type Region = (typeof REGIONS)[number]
 
@@ -11,10 +11,10 @@ export const STYLES = ['sans', 'serif'] as const
 export type Style = (typeof STYLES)[number]
 
 /**
- * What the detail page compares: the five regions, plus Japan's pre-reform
- * form where a row has one. The list pages compare regions alone.
+ * Display order for the five regions and Japan's pre-reform form. Keeping this
+ * separate from REGIONS lets generated tuples retain their stable data shape.
  */
-export const COLUMNS = [...REGIONS, 'old'] as const
+export const COLUMNS = ['cn', 'jp', 'old', 'hk', 'tw', 'kr'] as const
 export type Column = (typeof COLUMNS)[number]
 
 /** Korea is available as an opt-in comparison; all other columns start on. */