diff --git a/docs/development/current/main/10-Now.md b/docs/development/current/main/10-Now.md
index e3bc2379..6303d64e 100644
--- a/docs/development/current/main/10-Now.md
+++ b/docs/development/current/main/10-Now.md
@@ -1,6 +1,13 @@
 # Self Current Task — Now (main)
 
-## Current Focus: Phase 287 P9（Phase closeout）
+## Current Focus: Phase 287 Complete ✅ / Next: Backlog review
+
+**2025-12-27: Phase 287 完了** ✅
+- P0-P8完了（big files modularization / facade pattern / SSOT establishment）
+- P9: Phase closeout完了（docs更新）
+- 検証: quick 154/154 PASS維持、意味論不変
+- 入口: `docs/development/current/main/phases/phase-287/README.md`
+- **Next**: `docs/development/current/main/30-Backlog.md` から次タスク選定
 
 **2025-12-27: Phase 188.3 完了** ✅
 - Pattern6（NestedLoopMinimal）: `apps/tests/phase1883_nested_minimal.hako` が RC=9
diff --git a/docs/development/current/main/30-Backlog.md b/docs/development/current/main/30-Backlog.md
index 9aa7d53f..b5501e2e 100644
--- a/docs/development/current/main/30-Backlog.md
+++ b/docs/development/current/main/30-Backlog.md
@@ -13,10 +13,10 @@ Related:
   - SSOT: `docs/reference/language/repl.md`
   - 次: Phase 288.2+（任意）: REPL UX improvements（history / multiline / load 等）
 
-- **Phase 287（closeout）: Developer Hygiene（意味論不変）**
-  - 状況: P0–P8 ✅ 完了（big files / facade / SSOT / docs guard）
-  - 次（P9）: Phase closeout（docs-only）
-  - 指示書: `docs/development/current/main/phases/phase-287/P9-PHASE-CLOSEOUT-INSTRUCTIONS.md`
+- **Phase 287（✅ COMPLETE）: Developer Hygiene（意味論不変）**
+  - 状況: P0–P9 ✅ 完了（big files / facade / SSOT / docs guard / closeout）
+  - 成果: merge/mod.rs (1,555→1,053行), ast_feature_extractor (1,148→135行), plan.rs (741→120行)
+  - 入口: `docs/development/current/main/phases/phase-287/README.md`
 
 - **Phase 284（✅ COMPLETE）: Return as ExitKind SSOT（patternに散らさない）**
   - 目的: `return` を “pattern最適化の個別実装” にせず、`ExitKind` と `compose::*` / `emit_frag()` に収束させる
diff --git a/docs/development/current/main/phases/phase-287/README.md b/docs/development/current/main/phases/phase-287/README.md
index 08d612b9..de64b2d5 100644
--- a/docs/development/current/main/phases/phase-287/README.md
+++ b/docs/development/current/main/phases/phase-287/README.md
@@ -1,6 +1,6 @@
 # Phase 287: Developer Hygiene（big files / smoke / normalizer）
 
-**Status**: In progress (P0/P1/P2/P3/P4/P5/P6/P7 complete, P8 next)
+**Status**: Complete (P0-P8)
 **Date**: 2025-12-27
 **Previous**: Phase 286 (Plan Line完全運用化)
 
@@ -65,10 +65,38 @@ Phase 287 は「開発導線の整備（意味論不変）」を優先して、
 
 ---
 
-## Next (P8)
+## 2025-12-27 Update: Rewriter README / guard（P8）✅
 
-- `rewriter/` の README/責務ガードを追加して、SSOT（Plan→Apply）と “ここでは何をしないか” を明文化する。
+- `rewriter/README.md` を追加し、責務境界と SSOT（Plan→Apply）を明文化した（docs-only）。
   - 指示書: `docs/development/current/main/phases/phase-287/P8-REWRITER-README-GUARD-INSTRUCTIONS.md`
+  - 成果物: `src/mir/builder/control_flow/joinir/merge/rewriter/README.md`
+
+---
+
+## 2025-12-27 Update: Phase closeout（P9）✅
+
+- Phase 287 完了状態を docs に反映し、Now/Backlog を次フェーズへ切り替えた（docs-only）。
+  - 指示書: `docs/development/current/main/phases/phase-287/P9-PHASE-CLOSEOUT-INSTRUCTIONS.md`
+
+---
+
+## Summary
+
+**Phase 287 完了項目（P0-P8）**:
+- ✅ P0: `merge/mod.rs` modularization (1,555 → 1,053 lines)
+- ✅ P1: `ast_feature_extractor.rs` facade化 (1,148 → 135 lines)
+- ✅ P2: `contract_checks.rs` facade化 & 契約単位分割
+- ✅ P3: `instruction_rewriter.rs` stage分割 (Scan/Plan/Apply)
+- ✅ P4: `rewriter/stages/plan.rs` facade化 (741 → 120 lines)
+- ✅ P5: `stages/mod.rs` facade & re-export統一
+- ✅ P6: Scan stage削除 (Plan→Apply 2-stage pipeline)
+- ✅ P7: 未使用Box雛形削除 (apply_box, tail_call_detector_box, parameter_binding_box)
+- ✅ P8: `rewriter/README.md` 追加 (責務境界明文化)
+- ✅ P9: Phase closeout (docs更新)
+
+**検証結果**: quick 154/154 PASS維持、意味論不変
+
+**Next**: None (Phase 287 complete)
 
 ## Legacy / Historical (2025-12-26 plan)