diff --git a/src/llvm_py/builders/entry.py b/src/llvm_py/builders/entry.py
index dca95630..2d750463 100644
--- a/src/llvm_py/builders/entry.py
+++ b/src/llvm_py/builders/entry.py
@@ -1,5 +1,9 @@
 from typing import Optional
 import os
+import sys
+# NamingBox SSOT: Add parent directory to path for naming_helper import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
+from naming_helper import encode_static_method
 
 def ensure_ny_main(builder) -> None:
     """Ensure ny_main wrapper exists by delegating to Main.main/1 or main().
@@ -8,8 +12,10 @@ def ensure_ny_main(builder) -> None:
     has_ny_main = any(f.name == 'ny_main' for f in builder.module.functions)
     fn_main_box = None
     fn_main_plain = None
+    # NamingBox SSOT: Use encode_static_method for name comparison
+    main_box_name = encode_static_method("Main", "main", 1)
     for f in builder.module.functions:
-        if f.name == 'Main.main/1':
+        if f.name == main_box_name:
             fn_main_box = f
         elif f.name == 'main':
             fn_main_plain = f
diff --git a/src/llvm_py/instructions/boxcall.py b/src/llvm_py/instructions/boxcall.py
index dca6b1ff..45f6f34b 100644
--- a/src/llvm_py/instructions/boxcall.py
+++ b/src/llvm_py/instructions/boxcall.py
@@ -6,6 +6,7 @@ Core of Nyash's "Everything is Box" philosophy
 import llvmlite.ir as ir
 from typing import Dict, List, Optional, Any
 from instructions.safepoint import insert_automatic_safepoint
+from naming_helper import encode_static_method
 
 def _declare(module: ir.Module, name: str, ret, args):
     for f in module.functions:
@@ -431,9 +432,9 @@ def lower_boxcall(
     except Exception:
         pass
     if is_me and cur_fn_name.startswith('Main.'):
-        # Build target function name with arity
+        # NamingBox SSOT: Build target function name with arity
         arity = len(args)
-        target = f"Main.{method_name}/{arity}"
+        target = encode_static_method("Main", method_name, arity)
         # If module already has such function, prefer direct call
         callee = None
         for f in module.functions:
diff --git a/src/llvm_py/instructions/call.py b/src/llvm_py/instructions/call.py
index 5773350d..b2ac4ff6 100644
--- a/src/llvm_py/instructions/call.py
+++ b/src/llvm_py/instructions/call.py
@@ -7,6 +7,7 @@ import llvmlite.ir as ir
 from typing import Dict, List, Optional, Any
 from trace import debug as trace_debug
 from instructions.safepoint import insert_automatic_safepoint
+from naming_helper import encode_static_method
 
 def lower_call(
     builder: ir.IRBuilder,
@@ -165,8 +166,13 @@ def lower_call(
     
     # Make the call
     result = builder.call(func, call_args, name=f"call_{func_name}")
-    # Optional trace for final debugging
-    if isinstance(actual_name, str) and actual_name in ("Main.node_json/3", "Main.esc_json/1", "main"):
+    # NamingBox SSOT: Optional trace for final debugging
+    traced_names = (
+        encode_static_method("Main", "node_json", 3),
+        encode_static_method("Main", "esc_json", 1),
+        "main"
+    )
+    if isinstance(actual_name, str) and actual_name in traced_names:
         trace_debug(f"[TRACE] call {actual_name} args={len(call_args)}")
     
     # Store result if needed
diff --git a/src/llvm_py/naming_helper.py b/src/llvm_py/naming_helper.py
new file mode 100644
index 00000000..29886552
--- /dev/null
+++ b/src/llvm_py/naming_helper.py
@@ -0,0 +1,88 @@
+"""
+MIR NamingHelper — Python mirror of Rust src/mir/naming.rs
+
+Responsibility:
+- Encode/decode static box methods to MIR function names.
+- Centralize naming rules (e.g., Main._nop/0) for Builder/PyVM consistency.
+- Minimal: handle `main.*` → `Main.*` cases safely.
+
+Non-responsibility:
+- Dynamic dispatch or BoxFactory name resolution.
+- Entry point selection policy (NYASH_ENTRY).
+"""
+
+
+def encode_static_method(box_name: str, method: str, arity: int) -> str:
+    """
+    Encode a static box method into a MIR function name: `BoxName.method/arity`.
+
+    Args:
+        box_name: Raw box name (e.g., "main", "Main", "Calculator")
+        method: Method name (e.g., "main", "_nop", "add")
+        arity: Number of parameters (e.g., 0, 1, 3)
+
+    Returns:
+        Canonical MIR function name (e.g., "Main.main/1", "Main._nop/0")
+
+    Examples:
+        >>> encode_static_method("main", "main", 1)
+        'Main.main/1'
+        >>> encode_static_method("Main", "_nop", 0)
+        'Main._nop/0'
+        >>> encode_static_method("Calculator", "add", 2)
+        'Calculator.add/2'
+    """
+    return f"{canonical_box_name(box_name)}.{method}/{arity}"
+
+
+def canonical_box_name(raw: str) -> str:
+    """
+    Canonicalize a static box name for MIR-level usage.
+
+    Current rules:
+    - "main" → "Main" (minimal correction)
+    - Others: return as-is (avoid wide-scope spec changes)
+
+    Args:
+        raw: Raw box name (e.g., "main", "Main", "Calculator")
+
+    Returns:
+        Canonical box name (e.g., "Main", "Calculator")
+
+    Examples:
+        >>> canonical_box_name("main")
+        'Main'
+        >>> canonical_box_name("Main")
+        'Main'
+        >>> canonical_box_name("Calculator")
+        'Calculator'
+    """
+    return "Main" if raw == "main" else raw
+
+
+def normalize_static_global_name(func_name: str) -> str:
+    """
+    If `func_name` looks like a static box method like `main._nop/0`,
+    normalize the box part (`main` → `Main`) and return canonical form.
+
+    Args:
+        func_name: MIR function name (e.g., "main._nop/0", "Main.main/1", "print")
+
+    Returns:
+        Normalized function name (e.g., "Main._nop/0", "Main.main/1", "print")
+
+    Examples:
+        >>> normalize_static_global_name("main._nop/0")
+        'Main._nop/0'
+        >>> normalize_static_global_name("Main._nop/0")
+        'Main._nop/0'
+        >>> normalize_static_global_name("print")
+        'print'
+    """
+    if '.' in func_name:
+        box_part, rest = func_name.split('.', 1)
+        # rest contains "method/arity"
+        canon = canonical_box_name(box_part)
+        if canon != box_part:
+            return f"{canon}.{rest}"
+    return func_name
diff --git a/src/llvm_py/pyvm/intrinsic.py b/src/llvm_py/pyvm/intrinsic.py
index 77068869..959d1e10 100644
--- a/src/llvm_py/pyvm/intrinsic.py
+++ b/src/llvm_py/pyvm/intrinsic.py
@@ -5,11 +5,16 @@ from __future__ import annotations
 
 from typing import Any, List, Tuple
 import os
+import sys
+# NamingBox SSOT: Add parent directory to path for naming_helper import
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
+from naming_helper import encode_static_method
 
 
 def try_intrinsic(name: str, args: List[Any]) -> Tuple[bool, Any]:
     try:
-        if name == "Main.esc_json/1":
+        # NamingBox SSOT: Use encode_static_method for name comparison
+        if name == encode_static_method("Main", "esc_json", 1):
             s = "" if not args else ("" if args[0] is None else str(args[0]))
             out = []
             for ch in s:
@@ -41,7 +46,8 @@ def try_intrinsic(name: str, args: List[Any]) -> Tuple[bool, Any]:
             start = idx + len(key)
             ok, digits = try_intrinsic("MiniVm.read_digits/2", [js, start])
             return True, digits
-        if name == "Main.dirname/1":
+        # NamingBox SSOT: Use encode_static_method for name comparison
+        if name == encode_static_method("Main", "dirname", 1):
             p = "" if not args else ("" if args[0] is None else str(args[0]))
             d = os.path.dirname(p)
             if d == "":