diff --git a/data/uking_functions.csv b/data/uking_functions.csv
index 3db151bc..ca006143 100644
--- a/data/uking_functions.csv
+++ b/data/uking_functions.csv
@@ -40718,7 +40718,7 @@ Address,Quality,Size,Name
 0x0000007100689ec8,O,000048,_ZN5uking5query11CheckE3ModeC1ERKN4ksys3act2ai5Query7InitArgE
 0x0000007100689ef8,O,000020,_ZN5uking5query11CheckE3ModeD1Ev
 0x0000007100689f0c,O,000052,_ZN5uking5query11CheckE3ModeD0Ev
-0x0000007100689f40,U,000104,AI_Query_CheckE3Mode::doQuery
+0x0000007100689f40,O,000104,_ZN5uking5query11CheckE3Mode7doQueryEv
 0x0000007100689fa8,O,000004,_ZN5uking5query11CheckE3Mode10loadParamsERKN4evfl8QueryArgE
 0x0000007100689fac,O,000004,_ZN5uking5query11CheckE3Mode10loadParamsEv
 0x0000007100689fb0,O,000204,_ZNK5uking5query11CheckE3Mode27checkDerivedRuntimeTypeInfoEPKN4sead15RuntimeTypeInfo9InterfaceE
diff --git a/src/Game/AI/Query/queryCheckE3Mode.cpp b/src/Game/AI/Query/queryCheckE3Mode.cpp
index 45617654..88bb4056 100644
--- a/src/Game/AI/Query/queryCheckE3Mode.cpp
+++ b/src/Game/AI/Query/queryCheckE3Mode.cpp
@@ -1,5 +1,6 @@
 #include "Game/AI/Query/queryCheckE3Mode.h"
 #include <evfl/Query.h>
+#include "Game/E3Mgr.h"
 
 namespace uking::query {
 
@@ -7,9 +8,20 @@ CheckE3Mode::CheckE3Mode(const InitArg& arg) : ksys::act::ai::Query(arg) {}
 
 CheckE3Mode::~CheckE3Mode() = default;
 
-// FIXME: implement
 int CheckE3Mode::doQuery() {
-    return -1;
+    auto* e3m = E3Mgr::instance();
+    if (e3m != nullptr) {
+        if (e3m->isDemoMode0AndNotStageSelect()) {
+            return 1;
+        }
+        if (e3m->isDemoMode1AndNotStageSelect()) {
+            return 2;
+        }
+        if (e3m->isDemoMode2AndNotStageSelect()) {
+            return 3;
+        }
+    }
+    return 0;
 }
 
 void CheckE3Mode::loadParams(const evfl::QueryArg& arg) {}