diff --git a/docs/development/current/main/10-Now.md b/docs/development/current/main/10-Now.md
index 66519fc6..57c0b691 100644
--- a/docs/development/current/main/10-Now.md
+++ b/docs/development/current/main/10-Now.md
@@ -1,5 +1,13 @@
 # Self Current Task — Now (main)
 
+## 2025-12-17：Phase 100 P1 完了 ✅
+
+**Phase 100 P1: Pinned Local Captures**
+- CapturedEnv に CapturedKind (Explicit/Pinned) 拡張
+- PinnedLocalAnalyzer で loop-outer read-only locals を識別
+- Pinned receiver (例: s.substring()) が loop 内で使用可能に
+- Fixture/smoke で動作確認済み
+
 ## 2025‑12‑17：Phase 99 完了 ✅
 
 **Phase 99: Trim/escape 実コード寄り強化（VM+LLVM EXE）**
diff --git a/docs/development/current/main/phases/phase-100/README.md b/docs/development/current/main/phases/phase-100/README.md
index 7a02b6e2..c7139336 100644
--- a/docs/development/current/main/phases/phase-100/README.md
+++ b/docs/development/current/main/phases/phase-100/README.md
@@ -42,3 +42,42 @@ loop(i < n) {
 - **P2（mutable）**: loop body 内で再代入される外側変数は `Pinned` では扱わず、LoopState（carrier/env）に昇格して運ぶ。
   - 初期は “更新形を限定” して shape guard を作り、未対応は Fail‑Fast（曖昧に通さない）
 - **P3（hoist）**: ループ内の不変式の巻き上げは Loop Canonicalizer 側で扱う（別ユースケースとして分離）
+
+## P1: Pinned Local Captures (Explicit/Pinned) - 完了 ✅
+
+Implemented CapturedKind enum to distinguish:
+- **Explicit**: Traditional captures (condition variables, carriers)
+- **Pinned**: Phase 100 read-only loop-outer locals used as method receivers
+
+**Status**: P1-1 through P1-5 complete - pinned receiver functionality validated with fixture+smoke tests.
+
+Example (now works):
+```hako
+local s = "a" + "b" + "c"    # Dynamic construction (loop-outer)
+loop(i < 1) {
+    local ch = s.substring(i, i+1)  # Pinned receiver works!
+    print(i)
+    i = i + 1
+}
+```
+
+**Smoke test**: phase100_pinned_local_receiver_vm.sh
+
+### Implementation Details
+
+**Search Order (SSOT)**:
+1. ConditionEnv (loop-outer scope)
+2. LoopBodyLocalEnv (body-local variables - Phase 226 cascading)
+3. CapturedEnv (pinned loop-outer locals)
+4. CarrierInfo (mutable carriers)
+
+**Key Components**:
+- `CapturedKind` enum: Distinguishes Explicit vs Pinned captures
+- `PinnedLocalAnalyzer`: Identifies loop-outer read-only locals
+- `loop_body_local_init.rs`: Updated receiver resolution with full search order
+
+### Test Coverage
+
+- **Fixture**: `apps/tests/phase100_pinned_local_receiver_min.hako`
+- **Smoke Test**: `tools/smokes/v2/profiles/integration/apps/phase100_pinned_local_receiver_vm.sh`
+- **Regression**: Phase 96 and Phase 94 smoke tests pass