diff --git a/AGENTS.md b/AGENTS.md
index 8d7e686..197e73f 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -119,7 +119,7 @@ src/client/       React app, service worker, manifest
                   theme.ts — dark or light, and what a game hue reads as on each
 scripts/          build-feed.ts, build-static.ts, parse-fixture.ts (offline), refresh-sources.ts (fetches)
 serve.ts          static server + /api/health
-test/             683 tests
+test/             686 tests
 fixtures/<game>/  raw HTML + .expected.json per source — pinned, kept forever
 snapshots/        current page per source, rewritten by refresh — see its README
 ```
diff --git a/docs/INGESTION.md b/docs/INGESTION.md
index 4e9f9b5..92cabaf 100644
--- a/docs/INGESTION.md
+++ b/docs/INGESTION.md
@@ -338,9 +338,10 @@ Only meaningful when a game has more than one source; a single-source game passe
 
 `mergeEvents(groups)` compares events across sources:
 
-1. **Same ID** → same event; keep the higher-confidence copy.
-2. **Near match** — same game, title similarity ≥ 0.80, starts within 24h — → same event under
-   different titles; keep the higher-confidence copy.
+1. **Same ID** → same event; keep the higher-confidence copy. Applies within a source as well as
+   across sources — an identical id is the same row seen twice, whatever it is called.
+2. **Near match** — **different sources**, same game, title similarity ≥ 0.80, starts within 24h —
+   → same event under different titles; keep the higher-confidence copy.
 3. **Otherwise** → distinct events; keep both.
 
 Title similarity alone would merge a rerun with its original, since reruns reuse the name. The
@@ -348,6 +349,23 @@ start-date proximity check is the actual guard; the title threshold is deliberat
 that "Stygian Onslaught" and "Stygian Onslaught Event" collapse into one row rather than showing
 the user a duplicate.
 
+**Near matching is cross-source only, and that restriction is load-bearing** (2026-08-19). Fusing
+two rows from *one* page overrules a distinction the publisher made on purpose, and the loose
+threshold that makes rule 2 useful across sources makes it actively wrong within one: Game8's
+Umamusume banner list runs `3 Star Guaranteed 1.5 Anniversary Scout (Character)` and `(Support)`
+concurrently, titles differing by a single parenthetical and starting the same day. That scores far
+above 0.80, and fusing them dropped a live banner off the calendar with nothing anywhere reporting
+it — a silent drop, which § Silent drops ranks as the dangerous failure. Rule 1 still fuses repeats
+within a source, so nothing is duplicated; the parsers dedupe by id before merge is reached anyway.
+
+**Agreement raises confidence (+0.10) only across different `sourceId`s.** The same row seen twice
+in one document is not corroboration.
+
+**Disagreement is surfaced, never averaged.** Two sources whose `endsAt` differ by more than 24
+hours produce a `conflicts` entry; the pipeline routes those to quarantine. Splitting the difference
+between two dates would produce a value neither source asserts — the worst possible answer for a
+product whose promise is date accuracy.
+
 ## Stage 4 — validate
 
 Zod parse against `GachaEvent`, then calendar sanity rules. Anything failing a hard rule goes to
diff --git a/src/ingest/merge.ts b/src/ingest/merge.ts
index 6792153..5ca823a 100644
--- a/src/ingest/merge.ts
+++ b/src/ingest/merge.ts
@@ -124,6 +124,18 @@ function isSameEvent(
 ): boolean {
   if (a.id === b.id) return true;
 
+  // Near-match fusion reconciles two *sources* describing one event under
+  // different titles. Within one source it has no such job to do: the page has
+  // already told us these are two rows, the parser has already dropped repeats
+  // of the same id, and fusing them here overrules a distinction the publisher
+  // made on purpose. Game8's Umamusume page is the case that surfaced it — its
+  // `3 Star Guaranteed 1.5 Anniversary Scout (Character)` and `(Support)` are
+  // two concurrent banners whose titles differ by one parenthetical, which
+  // scores far above any workable threshold and starts on the same day. Fusing
+  // them dropped a real banner off the calendar with nothing reporting it,
+  // which is the silent drop this codebase treats as the dangerous failure.
+  if (a.sourceId === b.sourceId) return false;
+
   // Overlap alone misses a source that appends a qualifier: "Bedazzling
   // Dawnstar" vs "Bedazzling Dawnstar Sign-In" scores 0.67, well under any
   // safe threshold, yet is plainly one event.
diff --git a/test/merge.test.ts b/test/merge.test.ts
index 31fd70e..b8d10e9 100644
--- a/test/merge.test.ts
+++ b/test/merge.test.ts
@@ -191,3 +191,50 @@ describe("merging two sources for one game", () => {
     expect(conflicts[0]?.field).toBe("endsAt");
   });
 });
+
+describe("near matches within one source", () => {
+  test("two rows from one page stay two events", () => {
+    // The page has already told us these are two things, and the parser has
+    // already dropped repeats of the same id — so fusing them here overrules a
+    // distinction the publisher made on purpose. Game8's Umamusume banner list
+    // is the real case: two concurrent banners whose titles differ by one
+    // parenthetical and which start on the same day. Fusing them dropped a live
+    // banner off the calendar with nothing reporting it.
+    const character = event({
+      id: "uma:3-star-guaranteed-1-5-anniversary-scout-character:2026-07-22",
+      game: "uma",
+      title: "3 Star Guaranteed 1.5 Anniversary Scout (Character)",
+      sourceId: "uma-game8-events",
+    });
+    const support = event({
+      id: "uma:3-star-guaranteed-1-5-anniversary-scout-support:2026-07-22",
+      game: "uma",
+      title: "3 Star Guaranteed 1.5 Anniversary Scout (Support)",
+      sourceId: "uma-game8-events",
+    });
+
+    const merged = mergeEvents([[character, support]]);
+    expect(merged.events).toHaveLength(2);
+    expect(merged.conflicts).toHaveLength(0);
+  });
+
+  test("the same id twice from one source is still one event", () => {
+    // The exception that keeps the rule safe: an identical id is the same row
+    // seen twice, whatever it is called.
+    const once = event({ sourceId: "source-a" });
+    const twice = event({ sourceId: "source-a", title: "Test Event (again)" });
+    expect(mergeEvents([[once, twice]]).events).toHaveLength(1);
+  });
+
+  test("near matches across two sources still fuse", () => {
+    // The behaviour this rule narrows, not removes: reconciling two sources
+    // that describe one event under different titles is the whole job.
+    const a = event({ title: "Bedazzling Dawnstar", sourceId: "source-a" });
+    const b = event({
+      id: "genshin:bedazzling-dawnstar-sign-in:2026-08-12",
+      title: "Bedazzling Dawnstar Sign-In",
+      sourceId: "source-b",
+    });
+    expect(mergeEvents([[a], [b]]).events).toHaveLength(1);
+  });
+});