diff --git a/docs/README.md b/docs/README.md
index 9939b1f..b0dae1f 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -9,28 +9,28 @@
 
 ## Decisions & specs
 
-| Doc | What's in it |
-| --- | --- |
-| [`adr.md`](adr.md) | Architecture Decision Records — the load-bearing technical choices and why. |
-| [`v0.1-mvp-product.md`](v0.1-mvp-product.md) | v0.1 product design — boot, type one file, `Ctrl-S` to save, `Ctrl-G` to publish. |
-| [`v0.1-mvp-technical.md`](v0.1-mvp-technical.md) | v0.1 technical design — single Rust binary on `esp-idf-rs`, modules, threads, bring-up order. |
-| [`macroplan.md`](macroplan.md) | Version-by-version plan; each release is a usable artifact, not a checkpoint. |
-| [`typoena-toml.md`](typoena-toml.md) | `.typoena.toml` reference — the git-tracked editor preferences (auto-save, format-on-save, line numbers, auto-sync). |
-| [`hardware.md`](hardware.md) | Part choices for the bench build and the rationale behind them. |
+| Doc                                              | What's in it                                                                                                         |
+| ------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------- |
+| [`adr.md`](adr.md)                               | Architecture Decision Records — the load-bearing technical choices and why.                                          |
+| [`v0.1-mvp-product.md`](v0.1-mvp-product.md)     | v0.1 product design — boot, type one file, `Ctrl-S` to save, `Ctrl-G` to publish.                                    |
+| [`v0.1-mvp-technical.md`](v0.1-mvp-technical.md) | v0.1 technical design — single Rust binary on `esp-idf-rs`, modules, threads, bring-up order.                        |
+| [`macroplan.md`](macroplan.md)                   | Version-by-version plan; each release is a usable artifact, not a checkpoint.                                        |
+| [`typoena-toml.md`](typoena-toml.md)             | `.typoena.toml` reference — the git-tracked editor preferences (auto-save, format-on-save, line numbers, auto-sync). |
+| [`hardware.md`](hardware.md)                     | Part choices for the bench build and the rationale behind them.                                                      |
 
 ## Quality method
 
-| Doc | What's in it |
-| --- | --- |
-| [`qfd.md`](qfd.md) | Quality Function Deployment — turns user-facing requirements into technical HOWs; §3 is the filled 14 WHATs × 14 HOWs House of Quality. |
-| [`quality-house-empty.md`](quality-house-empty.md) | The House chassis, blank — for re-scoring from scratch. |
+| Doc                                                | What's in it                                                                                                                            |
+| -------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------- |
+| [`qfd.md`](qfd.md)                                 | Quality Function Deployment — turns user-facing requirements into technical HOWs; §3 is the filled 14 WHATs × 14 HOWs House of Quality. |
+| [`quality-house-empty.md`](quality-house-empty.md) | The House chassis, blank — for re-scoring from scratch.                                                                                 |
 
 ## Bench work
 
-| Area | What's in it |
-| --- | --- |
-| [`spikes.md`](spikes.md) | Rendering & UX spikes — display/UX risks proved outside the hardware stack. |
-| [`postmortems/`](postmortems/README.md) | Bring-up debugging write-ups: what broke, the root cause, and the decisions that came out of it. |
-| [`notes/`](notes/README.md) | Longer-form essays on the thinking behind specific choices — e.g. where the ~16 s cold [`:sync`](notes/sync-latency.md) goes. |
-| [`tradeoff-curves/`](tradeoff-curves/README.md) | Cost-vs-knob curves behind chosen defaults — energy, latency, memory. |
-| [`kaizen/real-repo-sync.md`](kaizen/real-repo-sync.md) | Six-step kaizen write-ups — the problem→analysis→fix story behind an improvement, e.g. the real-repo `:sync` brick. |
+| Area                                            | What's in it                                                                                                                                    |
+| ----------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------- |
+| [`spikes.md`](spikes.md)                        | Rendering & UX spikes — display/UX risks proved outside the hardware stack.                                                                     |
+| [`postmortems/`](postmortems/README.md)         | Bring-up debugging write-ups: what broke, the root cause, and the decisions that came out of it.                                                |
+| [`notes/`](notes/README.md)                     | Longer-form essays on the thinking behind specific choices — e.g. where the ~16 s cold [`:sync`](notes/sync-latency.md) goes.                   |
+| [`tradeoff-curves/`](tradeoff-curves/README.md) | Cost-vs-knob curves behind chosen defaults — energy, latency, memory.                                                                           |
+| [`kaizen/`](kaizen/README.md)                   | Six-step kaizen write-ups — the problem→analysis→fix story behind an improvement, e.g. the real-repo [`:sync` brick](kaizen/real-repo-sync.md). |
diff --git a/docs/kaizen/README.md b/docs/kaizen/README.md
new file mode 100644
index 0000000..e796091
--- /dev/null
+++ b/docs/kaizen/README.md
@@ -0,0 +1,16 @@
+# Kaizen
+
+> Six-step continuous-improvement write-ups: improvement potential → current
+> method analysis → ideas → test plan → implementation → evaluation. One file
+> per loop. Where a postmortem records how an incident was debugged, a kaizen
+> records how a recurring cost was measured, attacked, and re-measured — and
+> which standard changed so it stays fixed.
+>
+> Docs index: [`../README.md`](../README.md). Project overview:
+> [`../../README.md`](../../README.md). Sibling write-ups:
+> [`../postmortems/`](../postmortems/README.md) ·
+> [`../tradeoff-curves/`](../tradeoff-curves/README.md).
+
+| Kaizen                                                                                                                                                                                                                         | Status            |
+| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------- |
+| [`real-repo-sync.md`](real-repo-sync.md) — `:sync` (now `:gp`) never completes on the real notes repo: ∞ (device bricks) → 24.1 s measured, via the O(depth) TreeBuilder splice + a second localization loop on the push half. | Closed 2026-07-13 |