diff --git a/.yoi/tickets/00001KVFDX9AY/item.md b/.yoi/tickets/00001KVFDX9AY/item.md
index 60c297e1..a6d08f40 100644
--- a/.yoi/tickets/00001KVFDX9AY/item.md
+++ b/.yoi/tickets/00001KVFDX9AY/item.md
@@ -2,7 +2,7 @@
 title: 'Plugin: implement fs host API for Tool runtime'
 state: 'inprogress'
 created_at: '2026-06-19T07:53:13Z'
-updated_at: '2026-06-19T15:37:38Z'
+updated_at: '2026-06-19T15:39:09Z'
 assignee: null
 readiness: 'implementation_ready'
 risk_flags: ['plugin', 'fs', 'host-api', 'sandbox', 'path-safety', 'permission-grants', 'file-mutation']
diff --git a/.yoi/tickets/00001KVFDX9AY/thread.md b/.yoi/tickets/00001KVFDX9AY/thread.md
index fcd04c99..da21c12a 100644
--- a/.yoi/tickets/00001KVFDX9AY/thread.md
+++ b/.yoi/tickets/00001KVFDX9AY/thread.md
@@ -144,3 +144,32 @@ Next action:
 Ticket body/thread, relation metadata, orchestration plan records, related completed Tickets, Orchestrator worktree, visible Pods, existing branch/worktree, and bounded Plugin fs host API code context were checked. Depends-on blockers are closed, HTTPS host API and CLI inspection related work are closed, and no dirty-state blocker or missing planning decision was found. Component Model migration remains queued with migration/conflict waiting record. Accepting this queued Ticket for implementation before worktree/Pod side effects.
 
 ---
+
+<!-- event: implementation_report author: yoi-orchestrator at: 2026-06-19T15:39:09Z -->
+
+## Implementation report
+
+Implementation start note:
+
+`queued -> inprogress` acceptance、accepted plan、routing decision / IntentPacket、Component Model migration の waiting record を記録し、Orchestrator worktree で commit した後に、専用 implementation worktree と Coder Pod を起動した。
+
+Worktree:
+- `/home/hare/Projects/yoi/.worktree/00001KVFDX9AY-plugin-fs-host-api`
+- branch: `impl/00001KVFDX9AY-plugin-fs-host-api`
+
+Coder Pod:
+- `yoi-coder-00001KVFDX9AY`
+
+Scope / boundaries:
+- child runtime workspace root は read scope。
+- implementation worktree は write scope。
+- root/original workspace と Orchestrator worktree へは書き込まないよう指示済み。
+- `.yoi/memory`、runtime/log/lock/local/secret-like `.yoi` paths は編集しないよう指示済み。
+
+Related queued Ticket:
+- `00001KVG0HR96` Component Model migration remains queued due migration boundary / conflict with active fs host API work.
+
+Next:
+- Coder は scoped `fs` host API implementation、focused tests、validation、implementation commit を行い、実装報告を返す予定。
+
+---