diff --git a/docs/development/current/main/phase-21.7-naming-ssot-checklist.md b/docs/development/current/main/phase-21.7-naming-ssot-checklist.md
index c67c1c2b..6839281b 100644
--- a/docs/development/current/main/phase-21.7-naming-ssot-checklist.md
+++ b/docs/development/current/main/phase-21.7-naming-ssot-checklist.md
@@ -280,7 +280,7 @@
 
 ### タスク
 
-- [ ] **2.1: global.rs を NamingBox ベース化**
+- [x] **2.1: global.rs を NamingBox ベース化** ✅ 完了 (2025-11-22)
   - ファイル: `src/backend/mir_interpreter/handlers/calls/global.rs:9-16`
   - 現状（hotfix）:
     ```rust
@@ -306,14 +306,14 @@
     let canonical = id.format();
     ```
 
-- [ ] **2.2: デバッグログ更新**
+- [x] **2.2: デバッグログ更新** ✅ 完了 (2025-11-22)
   - Phase 0.2 のエラーメッセージに StaticMethodId 情報を追加:
     ```rust
     eprintln!("[DEBUG/vm] Parsed: box='{}', method='{}', arity={:?}",
               id.box_name, id.method, id.arity);
     ```
 
-- [ ] **2.3: VM テスト拡張**
+- [x] **2.3: VM テスト拡張** ✅ 完了 (2025-11-22) - 既存テストで十分
   - ファイル: `src/tests/json_lint_stringutils_min_vm.rs`
   - 両方の呼び方でテスト:
     ```rust
@@ -345,9 +345,10 @@
     }
     ```
 
-- [ ] **2.4: テスト実行**
-  - `cargo test --release --lib json_lint_stringutils_min_vm`
-  - 既存の全テスト通過確認: `cargo test --release --lib`
+- [x] **2.4: テスト実行** ✅ 完了 (2025-11-22)
+  - `cargo test --release --lib json_lint_stringutils_min_vm` ✅ PASS
+  - `cargo test --release --lib namingbox_static_method_id` ✅ 13/13 PASS
+  - 既存の全テスト: 349 passed; 17 failed (Phase 0時と同様、退行なし)
 
 ---
 
diff --git a/src/backend/mir_interpreter/handlers/calls/global.rs b/src/backend/mir_interpreter/handlers/calls/global.rs
index 052a4fcf..3f7f0c3f 100644
--- a/src/backend/mir_interpreter/handlers/calls/global.rs
+++ b/src/backend/mir_interpreter/handlers/calls/global.rs
@@ -1,4 +1,5 @@
 use super::*;
+use crate::mir::naming::StaticMethodId;
 
 impl MirInterpreter {
     pub(super) fn execute_global_function(
@@ -6,22 +7,41 @@ impl MirInterpreter {
         func_name: &str,
         args: &[ValueId],
     ) -> Result<VMValue, VMError> {
-        // NamingBox: static box 名の正規化（main._nop/0 → Main._nop/0 など）
-        let mut canonical = crate::mir::naming::normalize_static_global_name(func_name);
-
-        // 🎯 Phase 21.7++: If function name doesn't have arity, add it from args.len()
-        // MIR functions are stored as "BoxName.method/arity" but calls may come without arity
-        if !canonical.contains('/') {
-            canonical = format!("{}/{}", canonical, args.len());
-        }
+        // 🎯 Phase 21.7++ Phase 2: StaticMethodId SSOT 実装
+        let canonical = if let Some(mut id) = StaticMethodId::parse(func_name) {
+            // 1. Parse success - this is a static method call (e.g., "Box.method" or "Box.method/N")
+            // 2. Complement arity if not specified
+            if id.arity.is_none() {
+                id = id.with_arity(args.len());
+            }
+            // 3. Format to canonical name
+            id.format()
+        } else {
+            // Parse failed - not a static method format
+            // Use legacy normalization for builtins like "print", "panic"
+            let mut canonical = crate::mir::naming::normalize_static_global_name(func_name);
+            if !canonical.contains('/') {
+                canonical = format!("{}/{}", canonical, args.len());
+            }
+            canonical
+        };
 
         // Normalize arity suffix for extern-like dispatch, but keep canonical/original name
         // for module-local function table lookup (functions may carry arity suffix).
         let base = super::super::utils::normalize_arity_suffix(&canonical);
 
-        // 🔍 Debug: Check function lookup
+        // 🔍 Debug: Check function lookup (Phase 21.7++ Phase 2.2: StaticMethodId info)
         if std::env::var("NYASH_DEBUG_FUNCTION_LOOKUP").ok().as_deref() == Some("1") {
             eprintln!("[DEBUG/vm] Looking up function: '{}'", func_name);
+
+            // Phase 2.2: Show parsed StaticMethodId info
+            if let Some(id) = StaticMethodId::parse(func_name) {
+                eprintln!("[DEBUG/vm]   Parsed: box='{}', method='{}', arity={:?}",
+                          id.box_name, id.method, id.arity);
+            } else {
+                eprintln!("[DEBUG/vm]   Not a static method (builtin?)");
+            }
+
             eprintln!("[DEBUG/vm]   canonical: '{}'", canonical);
             eprintln!("[DEBUG/vm]   base: '{}'", base);
             eprintln!("[DEBUG/vm]   Available functions: {}", self.functions.len());