diff --git a/CLAUDE.md b/CLAUDE.md
index 2c2c9c72..f12a4b6f 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -71,7 +71,7 @@ Nyashは「Everything is Box」。実装・最適化・検証のすべてを「
 
 ### 実践方法
 1. **まず動くものを作る**（80%）
-2. **改善アイデアは `docs/ideas/` フォルダに記録**（20%）
+2. **改善アイデアは `docs/development/proposals/ideas/` フォルダに記録**（20%）
 3. **優先度に応じて後から改善**
 
 ## 🚀 クイックスタート
@@ -537,7 +537,7 @@ Call { func: ValueId, callee: Option<Callee> }  // 段階移行で破壊的変
 - 🎯 **All or Nothing**: Phase 10.7でPython transpilation、フォールバック無し設計
 - 📚 **完全ドキュメント化**: README.md導線、実装戦略、技術仕様すべて完備
 - 🗃️ **アーカイブ整理**: 古いphaseファイル群をarchiveに移動、導線クリーンアップ完了
-- 📋 詳細: [Property System仕様](docs/proposals/unified-members.md) | [Python統合計画](docs/development/roadmap/phases/phase-10.7/)
+- 📋 詳細: [Property System仕様](docs/development/proposals/unified-members.md) | [Python統合計画](docs/development/roadmap/phases/phase-10.7/)
 
 ## 📝 Update (2025-09-24) ✅ 改行処理革命Phase 2-B完了！実用レベル到達
 - 🎯 **改行処理革命Phase 2-B完了！** Box宣言系ファイルから14箇所のskip_newlines()完全削除
@@ -913,12 +913,12 @@ CODEX_MAX_CONCURRENT=2 CODEX_DEDUP=1 CODEX_ASYNC_DETACH=1 \
 pgrep -af 'codex.*exec'
 ```
 
-### 💡 アイデア管理（docs/ideas/フォルダ）
+### 💡 アイデア管理（docs/development/proposals/ideas/ フォルダ）
 
 **80/20ルールの「残り20%」を整理して管理**
 
 ```
-docs/ideas/
+docs/development/proposals/ideas/
 ├── improvements/     # 80%実装の残り20%改善候補
 ├── new-features/     # 新機能アイデア  
 └── other/           # その他すべて（調査、メモ、設計案）
diff --git a/CURRENT_TASK.md b/CURRENT_TASK.md
index d355f0fa..cf47265c 100644
--- a/CURRENT_TASK.md
+++ b/CURRENT_TASK.md
@@ -1114,7 +1114,7 @@ This page is trimmed to reflect the active work only. The previous long form has
   - Refreshed docs index with clear "Start here" links (blueprints/strings, EBNF, strings reference)
   - Clarified operator/loop sugar policy in `guides/language-core-and-sugar.md` ("!" adopted, do‑while not adopted)
   - Concurrency docs (design-only): box model, semantics, and patterns/checklist added
-    - `docs/proposals/concurrency/boxes.md`
+    - `docs/development/proposals/concurrency/boxes.md`
     - `docs/reference/concurrency/semantics.md`
     - `docs/guides/box-patterns.md`, `docs/guides/box-design-checklist.md`
 - CI/Smokes
@@ -1351,7 +1351,7 @@ Progress
 - Language: Flow blocks & `->` piping（design） — docs/development/design/legacy/flow-blocks.md
 - Guards: Range/CharClass sugar（reference） — docs/reference/language/match-guards.md
 - Strings: `toDigitOrNull` / `toIntOrNull`（design note） — docs/reference/language/strings.md
- - Concurrency: Box model（Routine/Channel/Select/Scope） — docs/proposals/concurrency/boxes.md
+- Concurrency: Box model（Routine/Channel/Select/Scope） — docs/development/proposals/concurrency/boxes.md
  - Concurrency semantics（blocking/close/select/trace） — docs/reference/concurrency/semantics.md
 
 ## Nyash VM めど後 — 機能追加リンク（備忘）
diff --git a/README.ja.md b/README.ja.md
index fdefaebb..01b456c4 100644
--- a/README.ja.md
+++ b/README.ja.md
@@ -30,11 +30,11 @@ Phase‑15（2025‑09）アップデート
 仕様と既知制約
 - 必須不変条件（Invariants）: `docs/reference/invariants.md`
 - 制約（既知/一時/解消済み）: `docs/reference/constraints.md`
-- PHI と SSA の設計: `docs/architecture/phi-and-ssa.md`
+- PHI と SSA の設計: `docs/reference/architecture/phi-and-ssa.md`
   - 既定のPHI挙動: Phase‑15 で PHI-ON（MIR14）が標準になったよ。ループ・break/continue・構造化制御の合流で PHI を必ず生成するよ。
   - レガシー互換: `NYASH_MIR_NO_PHI=1`（必要なら `NYASH_VERIFY_ALLOW_NO_PHI=1` も）で PHI-OFF（エッジコピー）に切り替えできるよ。
 - テスト行列（仕様→テスト対応）: `docs/guides/testing-matrix.md`
-- 他言語との比較: `docs/comparison/nyash-vs-others.md`
+- 他言語との比較: `docs/guides/comparison/nyash-vs-others.md`
 
 プロファイル（クイック）
 - `--profile dev` → マクロON（strict）、PyVM 開発向けの既定を適用（必要に応じて環境で上書き可）
diff --git a/README.md b/README.md
index 3ecd99a4..d0cf66fe 100644
--- a/README.md
+++ b/README.md
@@ -52,9 +52,9 @@ Profiles (quick)
 Specs & Constraints
 - Invariants (must-hold): `docs/reference/invariants.md`
 - Constraints (known/temporary/resolved): `docs/reference/constraints.md`
-- PHI & SSA design: `docs/architecture/phi-and-ssa.md`
+- PHI & SSA design: `docs/reference/architecture/phi-and-ssa.md`
 - Testing matrix (spec → tests): `docs/guides/testing-matrix.md`
-- Comparison with other languages: `docs/comparison/nyash-vs-others.md`
+- Comparison with other languages: `docs/guides/comparison/nyash-vs-others.md`
 
 ## Table of Contents
 - [Self‑Hosting (Dev Focus)](#self-hosting)
@@ -378,7 +378,7 @@ box DataProcessor {
 **Result**: Python code runs 10-50x faster as native Nyash binaries!
 
 ### Documentation
-- **[Property System Specification](docs/proposals/unified-members.md)** - Complete syntax reference
+- **[Property System Specification](docs/development/proposals/unified-members.md)** - Complete syntax reference
 - **[Python Integration Guide](docs/development/roadmap/phases/phase-10.7/)** - Python → Nyash transpilation
 - **[Implementation Strategy](docs/private/papers/paper-m-method-postfix-catch/implementation-strategy.md)** - Technical details
 
diff --git a/apps/lib/json_native/lexer/token.nyash b/apps/lib/json_native/lexer/token.nyash
index b14412d1..6ab77086 100644
--- a/apps/lib/json_native/lexer/token.nyash
+++ b/apps/lib/json_native/lexer/token.nyash
@@ -53,6 +53,13 @@ box JsonToken {
     get_line() { return me.line }
     get_column() { return me.column }
     
+    // 位置情報の設定（トークナイザーから付与）
+    set_line_column(line, column) {
+        me.line = line
+        me.column = column
+        return me
+    }
+    
     // ===== 判定メソッド =====
     
     is_literal() {
@@ -247,4 +254,4 @@ static box TokenStats {
             i = i + 1
         }
     }
-}
\ No newline at end of file
+}
diff --git a/apps/lib/json_native/lexer/tokenizer.nyash b/apps/lib/json_native/lexer/tokenizer.nyash
index 88682d54..d5aa9d00 100644
--- a/apps/lib/json_native/lexer/tokenizer.nyash
+++ b/apps/lib/json_native/lexer/tokenizer.nyash
@@ -66,37 +66,39 @@ box JsonTokenizer {
         
         // EOF チェック
         if me.scanner.is_eof() {
-            return new JsonToken("EOF", "", me.scanner.get_position(), me.scanner.get_position())
+            return new JsonToken("EOF", "", me.scanner.get_position(), me.scanner.get_position()).set_line_column(me.scanner.get_line(), me.scanner.get_column())
         }
         
         local start_pos = me.scanner.get_position()
+        local start_line = me.scanner.get_line()
+        local start_col = me.scanner.get_column()
         local ch = me.scanner.current()
         
         // 構造文字（単一文字）
         local structural_type = me.char_to_token_type(ch)
         if structural_type != null {
             me.scanner.advance()
-            return this.create_structural_token(structural_type, start_pos)
+            return this.create_structural_token(structural_type, start_pos).set_line_column(start_line, start_col)
         }
         
         // 文字列リテラル
         if ch == "\"" {
-            return me.tokenize_string()
+            return me.tokenize_string().set_line_column(start_line, start_col)
         }
         
         // 数値リテラル
         if me.is_number_start_char(ch) {
-            return me.tokenize_number()
+            return me.tokenize_number().set_line_column(start_line, start_col)
         }
         
         // キーワード（null, true, false）
         if me.is_alpha_char(ch) {
-            return me.tokenize_keyword()
+            return me.tokenize_keyword().set_line_column(start_line, start_col)
         }
         
         // 不明な文字（エラー）
         me.scanner.advance()
-        return new JsonToken("ERROR", "Unexpected character: '" + ch + "'", start_pos, me.scanner.get_position())
+        return new JsonToken("ERROR", "Unexpected character: '" + ch + "'", start_pos, me.scanner.get_position()).set_line_column(start_line, start_col)
     }
     
     // ===== 専用トークナイザーメソッド =====
diff --git a/apps/lib/json_native/utils/escape.nyash b/apps/lib/json_native/utils/escape.nyash
index d79d5ee3..6521a3a3 100644
--- a/apps/lib/json_native/utils/escape.nyash
+++ b/apps/lib/json_native/utils/escape.nyash
@@ -233,18 +233,110 @@ static box EscapeUtils {
                (ch >= "A" and ch <= "F")
     }
     
-    // 4桁の16進数文字列を文字に変換（簡易版）
+    // 4桁の16進数文字列を文字に変換（MVP: BMPの基本ASCIIとサロゲート検知）
     hex_to_char(hex) {
-        // 簡易実装: 基本的なASCII文字のみ対応
-        return match hex {
-            "0020" => " ",   // スペース
-            "0021" => "!",   // 感嘆符
-            "0022" => "\"",  // ダブルクォート
-            "005C" => "\\",  // バックスラッシュ
-            "0041" => "A",   // A
-            "0061" => "a",   // a
-            _ => "?"      // 不明な文字は?で代替
+        // サロゲート半の範囲は '?' に置換（結合は現段階で未対応）
+        if hex >= "D800" and hex <= "DFFF" {
+            return "?"
         }
+        // 簡易: よく使う範囲（0x20-0x7E）を網羅
+        if hex == "005C" { return "\\" }
+        if hex == "0022" { return "\"" }
+        // 0-9, A-Z, a-z, 空白と基本記号
+        if hex == "0020" { return " " }
+        if hex == "0021" { return "!" }
+        if hex == "0023" { return "#" }
+        if hex == "0024" { return "$" }
+        if hex == "0025" { return "%" }
+        if hex == "0026" { return "&" }
+        if hex == "0027" { return "'" }
+        if hex == "0028" { return "(" }
+        if hex == "0029" { return ")" }
+        if hex == "002A" { return "*" }
+        if hex == "002B" { return "+" }
+        if hex == "002C" { return "," }
+        if hex == "002D" { return "-" }
+        if hex == "002E" { return "." }
+        if hex == "002F" { return "/" }
+        if hex == "0030" { return "0" }
+        if hex == "0031" { return "1" }
+        if hex == "0032" { return "2" }
+        if hex == "0033" { return "3" }
+        if hex == "0034" { return "4" }
+        if hex == "0035" { return "5" }
+        if hex == "0036" { return "6" }
+        if hex == "0037" { return "7" }
+        if hex == "0038" { return "8" }
+        if hex == "0039" { return "9" }
+        if hex == "003A" { return ":" }
+        if hex == "003B" { return ";" }
+        if hex == "003C" { return "<" }
+        if hex == "003D" { return "=" }
+        if hex == "003E" { return ">" }
+        if hex == "003F" { return "?" }
+        if hex == "0040" { return "@" }
+        if hex == "0041" { return "A" }
+        if hex == "0042" { return "B" }
+        if hex == "0043" { return "C" }
+        if hex == "0044" { return "D" }
+        if hex == "0045" { return "E" }
+        if hex == "0046" { return "F" }
+        if hex == "0047" { return "G" }
+        if hex == "0048" { return "H" }
+        if hex == "0049" { return "I" }
+        if hex == "004A" { return "J" }
+        if hex == "004B" { return "K" }
+        if hex == "004C" { return "L" }
+        if hex == "004D" { return "M" }
+        if hex == "004E" { return "N" }
+        if hex == "004F" { return "O" }
+        if hex == "0050" { return "P" }
+        if hex == "0051" { return "Q" }
+        if hex == "0052" { return "R" }
+        if hex == "0053" { return "S" }
+        if hex == "0054" { return "T" }
+        if hex == "0055" { return "U" }
+        if hex == "0056" { return "V" }
+        if hex == "0057" { return "W" }
+        if hex == "0058" { return "X" }
+        if hex == "0059" { return "Y" }
+        if hex == "005A" { return "Z" }
+        if hex == "005B" { return "[" }
+        if hex == "005D" { return "]" }
+        if hex == "005E" { return "^" }
+        if hex == "005F" { return "_" }
+        if hex == "0060" { return "`" }
+        if hex == "0061" { return "a" }
+        if hex == "0062" { return "b" }
+        if hex == "0063" { return "c" }
+        if hex == "0064" { return "d" }
+        if hex == "0065" { return "e" }
+        if hex == "0066" { return "f" }
+        if hex == "0067" { return "g" }
+        if hex == "0068" { return "h" }
+        if hex == "0069" { return "i" }
+        if hex == "006A" { return "j" }
+        if hex == "006B" { return "k" }
+        if hex == "006C" { return "l" }
+        if hex == "006D" { return "m" }
+        if hex == "006E" { return "n" }
+        if hex == "006F" { return "o" }
+        if hex == "0070" { return "p" }
+        if hex == "0071" { return "q" }
+        if hex == "0072" { return "r" }
+        if hex == "0073" { return "s" }
+        if hex == "0074" { return "t" }
+        if hex == "0075" { return "u" }
+        if hex == "0076" { return "v" }
+        if hex == "0077" { return "w" }
+        if hex == "0078" { return "x" }
+        if hex == "0079" { return "y" }
+        if hex == "007A" { return "z" }
+        if hex == "007B" { return "{" }
+        if hex == "007C" { return "|" }
+        if hex == "007D" { return "}" }
+        if hex == "007E" { return "~" }
+        return "?"
     }
     
     // ===== 妥当性検証 =====
diff --git a/docs/guides/examples/README.md b/docs/guides/examples/README.md
index 299bf490..52734bb4 100644
--- a/docs/guides/examples/README.md
+++ b/docs/guides/examples/README.md
@@ -8,7 +8,7 @@ How to run (after full build):
   - `copyFrom = { method_id = 7, args = [ { kind = "box", category = "plugin" } ] }`
   - `cloneSelf = { method_id = 8 }`
 - Build the plugin: `cd plugins/nyash-filebox-plugin && cargo build --release`
-- Run the example: `./target/release/nyash docs/examples/plugin_boxref_return.nyash`
+- Run the example: `./target/release/nyash docs/guides/examples/plugin_boxref_return.nyash`
 
 Expected behavior:
 - Creates two FileBox instances (`f`, `g`), writes to `f`, copies content to `g` via `copyFrom`, then closes both.
diff --git a/docs/private/papers/reference/plugin-system/boxref-behavior.md b/docs/private/papers/reference/plugin-system/boxref-behavior.md
index 87c4a4c5..7a45ba3c 100644
--- a/docs/private/papers/reference/plugin-system/boxref-behavior.md
+++ b/docs/private/papers/reference/plugin-system/boxref-behavior.md
@@ -49,5 +49,4 @@
 ## 7. 参考
 - 仕様: `docs/reference/plugin-system/nyash-toml-v2_1-spec.md`
 - 実装: `src/runtime/plugin_loader_v2.rs`（引数検証/Handle戻り値復元）
-- 例: `docs/examples/plugin_boxref_return.nyash`
-
+- 例: `docs/guides/examples/plugin_boxref_return.nyash`
diff --git a/docs/reference/plugin-system/boxref-behavior.md b/docs/reference/plugin-system/boxref-behavior.md
index 87c4a4c5..7a45ba3c 100644
--- a/docs/reference/plugin-system/boxref-behavior.md
+++ b/docs/reference/plugin-system/boxref-behavior.md
@@ -49,5 +49,4 @@
 ## 7. 参考
 - 仕様: `docs/reference/plugin-system/nyash-toml-v2_1-spec.md`
 - 実装: `src/runtime/plugin_loader_v2.rs`（引数検証/Handle戻り値復元）
-- 例: `docs/examples/plugin_boxref_return.nyash`
-
+- 例: `docs/guides/examples/plugin_boxref_return.nyash`
diff --git a/src/llvm_py/README.md b/src/llvm_py/README.md
index ea4b116b..1dbd558a 100644
--- a/src/llvm_py/README.md
+++ b/src/llvm_py/README.md
@@ -2,7 +2,7 @@
 
 ## 📝 概要
 Rust/inkwellの複雑性を回避し、llvmliteを使ってシンプルに実装する実験的バックエンド。
-ChatGPTが設計した`docs/design/LLVM_LAYER_OVERVIEW.md`の設計原則に従う。
+ChatGPTが設計した`docs/development/design/legacy/LLVM_LAYER_OVERVIEW.md`の設計原則に従う。
 
 ## 🎯 目的
 1. **検証ハーネス** - PHI/SSA構造の高速検証
diff --git a/src/llvm_py/llvm_builder.py b/src/llvm_py/llvm_builder.py
index 67a945a2..7934a50b 100644
--- a/src/llvm_py/llvm_builder.py
+++ b/src/llvm_py/llvm_builder.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 """
 Nyash LLVM Python Backend - Main Builder
-Following the design principles in docs/design/LLVM_LAYER_OVERVIEW.md
+Following the design principles in docs/development/design/legacy/LLVM_LAYER_OVERVIEW.md
 """
 
 import json
diff --git a/src/llvm_py/resolver.py b/src/llvm_py/resolver.py
index 644f2995..f1e9f69f 100644
--- a/src/llvm_py/resolver.py
+++ b/src/llvm_py/resolver.py
@@ -12,7 +12,7 @@ import llvmlite.ir as ir
 class Resolver:
     """
     Centralized value resolution with per-block caching.
-    Following the Core Invariants from docs/design/LLVM_LAYER_OVERVIEW.md:
+    Following the Core Invariants from docs/development/design/legacy/LLVM_LAYER_OVERVIEW.md:
     - Resolver-only reads
     - Localize at block start (PHI creation)
     - Cache per (block, value) to avoid redundant PHIs
diff --git a/tools/aot_plan/README.md b/tools/aot_plan/README.md
index 665ba1d0..2c7e4082 100644
--- a/tools/aot_plan/README.md
+++ b/tools/aot_plan/README.md
@@ -1,6 +1,6 @@
 # Nyash AOT-Plan (Phase 15.1) — Scripts Skeleton
 
-This folder will contain Nyash scripts that analyze a project (following `using` imports) and emit `aot_plan.v1.json` per docs/design/aot-plan-v1.md.
+This folder will contain Nyash scripts that analyze a project (following `using` imports) and emit `aot_plan.v1.json` per docs/development/design/legacy/aot-plan-v1.md.
 
 Phase 15.1 scope:
 - Keep scripts minimal and deterministic
diff --git a/tools/ci_check_golden.sh b/tools/ci_check_golden.sh
index 6bec96c1..7284a40b 100644
--- a/tools/ci_check_golden.sh
+++ b/tools/ci_check_golden.sh
@@ -7,13 +7,13 @@ ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
 cd "$ROOT_DIR"
 
 PAIRS=(
-  "local_tests/typeop_is_as_func_poc.nyash docs/status/golden/typeop_is_as_func_poc.mir.txt"
-  "local_tests/typeop_is_as_poc.nyash docs/status/golden/typeop_is_as_poc.mir.txt"
-  "local_tests/extern_console_log.nyash docs/status/golden/extern_console_log.mir.txt"
-  "local_tests/simple_loop_test.nyash docs/status/golden/loop_simple.mir.txt"
-  "local_tests/test_vm_array_getset.nyash docs/status/golden/boxcall_array_getset.mir.txt"
-  "local_tests/typeop_mixed.nyash docs/status/golden/typeop_mixed.mir.txt"
-  "local_tests/loop_nested_if_test.nyash docs/status/golden/loop_nested_if.mir.txt"
+  "local_tests/typeop_is_as_func_poc.nyash docs/development/testing/golden/typeop_is_as_func_poc.mir.txt"
+  "local_tests/typeop_is_as_poc.nyash docs/development/testing/golden/typeop_is_as_poc.mir.txt"
+  "local_tests/extern_console_log.nyash docs/development/testing/golden/extern_console_log.mir.txt"
+  "local_tests/simple_loop_test.nyash docs/development/testing/golden/loop_simple.mir.txt"
+  "local_tests/test_vm_array_getset.nyash docs/development/testing/golden/boxcall_array_getset.mir.txt"
+  "local_tests/typeop_mixed.nyash docs/development/testing/golden/typeop_mixed.mir.txt"
+  "local_tests/loop_nested_if_test.nyash docs/development/testing/golden/loop_nested_if.mir.txt"
 )
 
 FAILED=0
diff --git a/tools/smokes/v2/profiles/quick/core/json_string_escapes_ast.sh b/tools/smokes/v2/profiles/quick/core/json_string_escapes_ast.sh
new file mode 100644
index 00000000..857c3ace
--- /dev/null
+++ b/tools/smokes/v2/profiles/quick/core/json_string_escapes_ast.sh
@@ -0,0 +1,63 @@
+#!/bin/bash
+# json_string_escapes_ast.sh - JSON string escapes roundtrip via AST using
+
+source "$(dirname "$0")/../../../lib/test_runner.sh"
+require_env || exit 2
+preflight_plugins || exit 2
+
+TEST_DIR="/tmp/json_string_escapes_ast_$$"
+mkdir -p "$TEST_DIR"
+cd "$TEST_DIR"
+
+cat > nyash.toml << EOF
+[using.json_native]
+path = "$NYASH_ROOT/apps/lib/json_native/"
+main = "parser/parser.nyash"
+
+[using.aliases]
+json = "json_native"
+EOF
+
+cat > driver.nyash << 'EOF'
+using json_native as JsonParserModule
+
+static box Main {
+  main() {
+    // input → expected stringify
+    local inputs = new ArrayBox()
+    local expect = new ArrayBox()
+
+    inputs.push("\"A\"");            expect.push("\"A\"")
+    inputs.push("\"\\n\" ");        expect.push("\"\\n\"")
+    inputs.push("\"\\t\"");         expect.push("\"\\t\"")
+    inputs.push("\"\\\\\"");        expect.push("\"\\\\\"")
+    inputs.push("\"\\\"\"");        expect.push("\"\\\"\"")
+    inputs.push("\"\\u0041\"");      expect.push("\"A\"")
+
+    local i = 0
+    loop(i < inputs.length()) {
+      local s = inputs.get(i)
+      local r = JsonParserModule.roundtrip_test(s)
+      print(r)
+      i = i + 1
+    }
+    return 0
+  }
+}
+EOF
+
+expected=$(cat << 'TXT'
+"A"
+"\n"
+"\t"
+"\\"
+"\""
+"A"
+TXT
+)
+
+output=$("$NYASH_BIN" --backend vm driver.nyash 2>&1 | filter_noise)
+compare_outputs "$expected" "$output" "json_string_escapes_ast"
+
+cd /
+rm -rf "$TEST_DIR"