diff --git a/app/src/main/java/com/example/research/core/util/NaturalSort.kt b/app/src/main/java/com/example/research/core/util/NaturalSort.kt
new file mode 100644
index 0000000..581ed6c
--- /dev/null
+++ b/app/src/main/java/com/example/research/core/util/NaturalSort.kt
@@ -0,0 +1,128 @@
+package com.example.research.core.util
+
+val NaturalStringComparator: Comparator<String> = Comparator { a, b -> compareNatural(a, b) }
+
+private const val NUMERAL_CAP = 1_000_000_000_000_000_000L
+
+private fun digitOf(c: Char): Int = when (c) {
+    '〇', '零' -> 0
+    '一', '壹', '壱', '弌' -> 1
+    '二', '貳', '贰', '弐', '弍', '兩', '两' -> 2
+    '三', '叁', '參', '参', '弎' -> 3
+    '四', '肆' -> 4
+    '五', '伍' -> 5
+    '六', '陸', '陆' -> 6
+    '七', '柒' -> 7
+    '八', '捌' -> 8
+    '九', '玖' -> 9
+    else -> Character.digit(c, 10)
+}
+
+private fun smallUnitOf(c: Char): Long = when (c) {
+    '十', '拾' -> 10L
+    '百', '佰' -> 100L
+    '千', '仟' -> 1000L
+    else -> 0L
+}
+
+private fun fixedTensOf(c: Char): Long = when (c) {
+    '廿' -> 20L
+    '卅' -> 30L
+    '卌' -> 40L
+    else -> 0L
+}
+
+private fun bigUnitOf(c: Char): Long = when (c) {
+    '万', '萬' -> 10_000L
+    '億', '亿' -> 100_000_000L
+    '兆' -> 1_000_000_000_000L
+    '京' -> 10_000_000_000_000_000L
+    else -> 0L
+}
+
+private fun isNumeralChar(c: Char): Boolean =
+    digitOf(c) >= 0 || smallUnitOf(c) > 0L || fixedTensOf(c) > 0L || bigUnitOf(c) > 0L
+
+private fun satMul(a: Long, b: Long): Long =
+    if (a != 0L && b > NUMERAL_CAP / a) NUMERAL_CAP else minOf(a * b, NUMERAL_CAP)
+
+private fun satAdd(a: Long, b: Long): Long = minOf(a + b, NUMERAL_CAP)
+
+private fun numeralValue(s: String, start: Int, end: Int): Long {
+    var total = 0L
+    var section = 0L
+    var pending = -1L
+    for (k in start until end) {
+        val c = s[k]
+        val digit = digitOf(c)
+        if (digit >= 0) {
+            pending = if (pending < 0) digit.toLong() else satAdd(satMul(pending, 10L), digit.toLong())
+            continue
+        }
+        val small = smallUnitOf(c)
+        if (small > 0L) {
+            section = satAdd(section, satMul(if (pending < 0) 1L else pending, small))
+            pending = -1
+            continue
+        }
+        val fixed = fixedTensOf(c)
+        if (fixed > 0L) {
+            section = satAdd(section, fixed)
+            pending = -1
+            continue
+        }
+        val base = satAdd(section, maxOf(pending, 0L))
+        total = satAdd(total, satMul(if (base == 0L) 1L else base, bigUnitOf(c)))
+        section = 0L
+        pending = -1
+    }
+    return satAdd(total, satAdd(section, maxOf(pending, 0L)))
+}
+
+private fun compareNatural(a: String, b: String): Int {
+    var i = 0
+    var j = 0
+    while (i < a.length && j < b.length) {
+        val ca = a[i]
+        val cb = b[j]
+        val asciiA = ca in '0'..'9'
+        val asciiB = cb in '0'..'9'
+        when {
+            !asciiA && !asciiB && isNumeralChar(ca) && isNumeralChar(cb) -> {
+                var endA = i
+                while (endA < a.length && isNumeralChar(a[endA])) endA++
+                var endB = j
+                while (endB < b.length && isNumeralChar(b[endB])) endB++
+                val diff = numeralValue(a, i, endA).compareTo(numeralValue(b, j, endB))
+                if (diff != 0) return diff
+                i = endA
+                j = endB
+            }
+            asciiA && asciiB -> {
+                var endA = i
+                while (endA < a.length && a[endA] in '0'..'9') endA++
+                var endB = j
+                while (endB < b.length && b[endB] in '0'..'9') endB++
+                var startA = i
+                while (startA < endA - 1 && a[startA] == '0') startA++
+                var startB = j
+                while (startB < endB - 1 && b[startB] == '0') startB++
+                val lengthA = endA - startA
+                val lengthB = endB - startB
+                if (lengthA != lengthB) return lengthA.compareTo(lengthB)
+                for (k in 0 until lengthA) {
+                    val diff = a[startA + k].compareTo(b[startB + k])
+                    if (diff != 0) return diff
+                }
+                i = endA
+                j = endB
+            }
+            else -> {
+                if (ca != cb) return ca.compareTo(cb)
+                i++
+                j++
+            }
+        }
+    }
+    return (a.length - i).compareTo(b.length - j)
+}
diff --git a/app/src/main/java/com/example/research/data/parser/SearchRanking.kt b/app/src/main/java/com/example/research/data/parser/SearchRanking.kt
index 4185480..e3887ef 100644
--- a/app/src/main/java/com/example/research/data/parser/SearchRanking.kt
+++ b/app/src/main/java/com/example/research/data/parser/SearchRanking.kt
@@ -1,6 +1,7 @@
 package com.example.research.data.parser
 
 import com.example.research.core.domain.model.IndexEntry
+import com.example.research.core.util.NaturalStringComparator
 import com.example.research.core.util.foldLatinDiacritics
 
 internal data class SearchRankingContext(
@@ -40,6 +41,11 @@ internal fun List<IndexEntry>.rankBySearchRelevance(
             entry = entry,
         )
     }
-        .sortedWith(compareBy({ it.matchTier }, { it.exactMatch }, { it.charCount }, { it.word }))
+        .sortedWith(
+            compareBy<SortKey> { it.matchTier }
+                .thenBy { it.exactMatch }
+                .thenBy { it.charCount }
+                .thenBy(NaturalStringComparator) { it.word }
+        )
         .map { it.entry }
 }