diff --git a/spec b/spec
index 8cba55b214..6740d7e1e8 100644
--- a/spec
+++ b/spec
@@ -2891,8 +2891,7 @@ beginseg
     name "ovl_Bg_Keikoku_Saku"
     compress
     include "build/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.o"
-    include "build/data/ovl_Bg_Keikoku_Saku/ovl_Bg_Keikoku_Saku.data.o"
-    include "build/data/ovl_Bg_Keikoku_Saku/ovl_Bg_Keikoku_Saku.reloc.o"
+    include "build/src/overlays/actors/ovl_Bg_Keikoku_Saku/ovl_Bg_Keikoku_Saku_reloc.o"
 endseg
 
 beginseg
diff --git a/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.c b/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.c
index 0e7488a9ab..24f18bb2f0 100644
--- a/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.c
+++ b/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.c
@@ -5,6 +5,7 @@
  */
 
 #include "z_bg_keikoku_saku.h"
+#include "objects/object_keikoku_obj/object_keikoku_obj.h"
 
 #define FLAGS 0x00000000
 
@@ -15,7 +16,10 @@ void BgKeikokuSaku_Destroy(Actor* thisx, GlobalContext* globalCtx);
 void BgKeikokuSaku_Update(Actor* thisx, GlobalContext* globalCtx);
 void BgKeikokuSaku_Draw(Actor* thisx, GlobalContext* globalCtx);
 
-#if 0
+void func_80A5389C(BgKeikokuSaku* this, GlobalContext* globalCtx);
+void func_80A538E0(BgKeikokuSaku* this, GlobalContext* globalCtx);
+void func_80A53994(BgKeikokuSaku* this, GlobalContext* globalCtx);
+
 const ActorInit Bg_Keikoku_Saku_InitVars = {
     ACTOR_BG_KEIKOKU_SAKU,
     ACTORCAT_ITEMACTION,
@@ -28,21 +32,71 @@ const ActorInit Bg_Keikoku_Saku_InitVars = {
     (ActorFunc)BgKeikokuSaku_Draw,
 };
 
-#endif
+void BgKeikokuSaku_Init(Actor* thisx, GlobalContext* globalCtx) {
+    s32 pad;
+    BgKeikokuSaku* this = THIS;
+    CollisionHeader* colHeader = NULL;
 
-extern UNK_TYPE D_06001640;
-extern UNK_TYPE D_06002300;
+    DynaPolyActor_Init(&this->dyna, 0);
+    CollisionHeader_GetVirtual(&object_keikoku_obj_Colheader_002300, &colHeader);
+    this->dyna.bgId = DynaPoly_SetBgActor(globalCtx, &globalCtx->colCtx.dyna, &this->dyna.actor, colHeader);
+    this->switchFlag = BGKEIKOKUSAKU_GET_SWITCHFLAG(thisx);
+    if (Flags_GetSwitch(globalCtx, this->switchFlag)) {
+        this->dyna.actor.world.pos.z = 2659.0f;
+    } else {
+        this->actionFunc = func_80A5389C;
+    }
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/overlays/ovl_Bg_Keikoku_Saku/BgKeikokuSaku_Init.s")
+void BgKeikokuSaku_Destroy(Actor* thisx, GlobalContext* globalCtx) {
+    BgKeikokuSaku* this = THIS;
 
-#pragma GLOBAL_ASM("asm/non_matchings/overlays/ovl_Bg_Keikoku_Saku/BgKeikokuSaku_Destroy.s")
+    DynaPoly_DeleteBgActor(globalCtx, &globalCtx->colCtx.dyna, this->dyna.bgId);
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/overlays/ovl_Bg_Keikoku_Saku/func_80A5389C.s")
+void func_80A5389C(BgKeikokuSaku* this, GlobalContext* globalCtx) {
+    if (Flags_GetSwitch(globalCtx, this->switchFlag)) {
+        this->actionFunc = func_80A538E0;
+    }
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/overlays/ovl_Bg_Keikoku_Saku/func_80A538E0.s")
+void func_80A538E0(BgKeikokuSaku* this, GlobalContext* globalCtx) {
+    Actor_PlaySfxAtPos(&this->dyna.actor, NA_SE_EV_METALGATE_OPEN - SFX_FLAG);
+    this->dyna.actor.world.pos.z -= 2.0f + BREG(8);
+    if (this->dyna.actor.world.pos.z < (BREG(9) + 2660.0f)) {
+        Actor_PlaySfxAtPos(&this->dyna.actor, NA_SE_EV_BRIDGE_OPEN_STOP);
+        this->timer = 30;
+        this->actionFunc = func_80A53994;
+    }
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/overlays/ovl_Bg_Keikoku_Saku/func_80A53994.s")
+void func_80A53994(BgKeikokuSaku* this, GlobalContext* globalCtx) {
+    if (this->timer == 0) {
+        this->actionFunc = func_80A5389C;
+    }
+}
 
-#pragma GLOBAL_ASM("asm/non_matchings/overlays/ovl_Bg_Keikoku_Saku/BgKeikokuSaku_Update.s")
+void BgKeikokuSaku_Update(Actor* thisx, GlobalContext* globalCtx) {
+    BgKeikokuSaku* this = THIS;
 
-#pragma GLOBAL_ASM("asm/non_matchings/overlays/ovl_Bg_Keikoku_Saku/BgKeikokuSaku_Draw.s")
+    if (this->timer) {
+        this->timer--;
+    }
+    this->dyna.actor.world.pos.x = BREG(5) + this->dyna.actor.home.pos.x;
+    this->dyna.actor.world.pos.y = BREG(6) + this->dyna.actor.home.pos.y;
+    this->dyna.actor.world.pos.z = BREG(7) + this->dyna.actor.home.pos.z;
+    this->dyna.actor.scale.x = (BREG(10) / 1000.0f) + 0.1f;
+    this->dyna.actor.scale.y = (BREG(11) / 1000.0f) + 0.1f;
+    this->dyna.actor.scale.z = (BREG(12) / 1000.0f) + 0.1f;
+    this->actionFunc(this, globalCtx);
+}
+
+void BgKeikokuSaku_Draw(Actor* thisx, GlobalContext* globalCtx) {
+    OPEN_DISPS(globalCtx->state.gfxCtx);
+
+    func_8012C2DC(globalCtx->state.gfxCtx);
+    gSPMatrix(POLY_XLU_DISP++, Matrix_NewMtx(globalCtx->state.gfxCtx), G_MTX_NOPUSH | G_MTX_LOAD | G_MTX_MODELVIEW);
+    gSPDisplayList(POLY_XLU_DISP++, object_keikoku_obj_DL_001640);
+
+    CLOSE_DISPS(globalCtx->state.gfxCtx);
+}
diff --git a/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.h b/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.h
index 6092edcb44..8fa6634609 100644
--- a/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.h
+++ b/src/overlays/actors/ovl_Bg_Keikoku_Saku/z_bg_keikoku_saku.h
@@ -3,17 +3,18 @@
 
 #include "global.h"
 
+#define BGKEIKOKUSAKU_GET_SWITCHFLAG(thisx) ((thisx)->params & 0x7F)
+
 struct BgKeikokuSaku;
 
 typedef void (*BgKeikokuSakuActionFunc)(struct BgKeikokuSaku*, GlobalContext*);
 
 typedef struct BgKeikokuSaku {
-    /* 0x0000 */ Actor actor;
-    /* 0x0144 */ char unk_144[0x18];
-    /* 0x015C */ BgKeikokuSakuActionFunc actionFunc;
-    /* 0x0160 */ char unk_160[0x4];
-} BgKeikokuSaku; // size = 0x164
-
+    /* 0x000 */ DynaPolyActor dyna;
+    /* 0x15C */ BgKeikokuSakuActionFunc actionFunc;
+    /* 0x160 */ s16 switchFlag;
+    /* 0x162 */ s16 timer;
+} BgKeikokuSaku; // Size = 0x164
 extern const ActorInit Bg_Keikoku_Saku_InitVars;
 
 #endif // Z_BG_KEIKOKU_SAKU_H
diff --git a/undefined_syms.txt b/undefined_syms.txt
index be8e812898..64a46e14c0 100644
--- a/undefined_syms.txt
+++ b/undefined_syms.txt
@@ -644,11 +644,6 @@ D_06012700 = 0x06012700;
 D_06012728 = 0x06012728;
 D_06012788 = 0x06012788;
 
-// ovl_Bg_Keikoku_Saku
-
-D_06001640 = 0x06001640;
-D_06002300 = 0x06002300;
-
 // ovl_Bg_Kin2_Bombwall
 
 D_06000128 = 0x06000128;