diff --git a/asm/non_matching/manager21/Manager21_Main.inc b/asm/non_matching/manager21/Manager21_Main.inc
deleted file mode 100644
index 87823c86..00000000
--- a/asm/non_matching/manager21/Manager21_Main.inc
+++ /dev/null
@@ -1,88 +0,0 @@
-	.syntax unified
-	push {r4, r5, r6, r7, lr}
-	mov r7, r8
-	push {r7}
-	adds r5, r0, #0
-	ldrb r1, [r5, #0xc]
-	cmp r1, #0
-	bne _0805B834
-	movs r0, #1
-	strb r0, [r5, #0xc]
-	str r1, [r5, #0x20]
-_0805B834:
-	ldrb r0, [r5, #0xa]
-	bl GetCurrentRoomProperty
-	adds r4, r0, #0
-	movs r7, #0
-	ldrh r0, [r4]
-	cmp r0, #0
-	beq _0805B8C4
-	ldr r0, _0805B8A8 @ =gRoomControls
-	mov r8, r0
-_0805B848:
-	ldrh r0, [r4]
-	ldrh r1, [r4, #2]
-	movs r2, #4
-	movs r3, #4
-	bl CheckRectOnScreen
-	cmp r0, #0
-	beq _0805B8AC
-	movs r6, #1
-	lsls r6, r7
-	ldr r0, [r5, #0x20]
-	ands r0, r6
-	cmp r0, #0
-	bne _0805B8B6
-	ldrh r0, [r4, #4]
-	bl sub_0805B8CC
-	cmp r0, #0
-	beq _0805B8B6
-	movs r0, #0x4e
-	movs r1, #1
-	movs r2, #0
-	bl CreateObject
-	adds r1, r0, #0
-	cmp r1, #0
-	beq _0805B8B6
-	ldrh r0, [r4, #6]
-	strb r0, [r1, #0xe]
-	strb r7, [r1, #0xf]
-	ldrh r0, [r4]
-	mov r2, r8
-	ldrh r2, [r2, #6]
-	adds r0, r0, r2
-	strh r0, [r1, #0x2e]
-	ldrh r0, [r4, #2]
-	mov r3, r8
-	ldrh r3, [r3, #8]
-	adds r0, r0, r3
-	strh r0, [r1, #0x32]
-	str r5, [r1, #0x50]
-	adds r0, r1, #0
-	bl sub_08016A30
-	ldr r0, [r5, #0x20]
-	orrs r0, r6
-	b _0805B8B4
-	.align 2, 0
-_0805B8A8: .4byte gRoomControls
-_0805B8AC:
-	movs r1, #1
-	lsls r1, r7
-	ldr r0, [r5, #0x20]
-	bics r0, r1
-_0805B8B4:
-	str r0, [r5, #0x20]
-_0805B8B6:
-	adds r4, #8
-	adds r7, #1
-	ldrh r0, [r4]
-	cmp r0, #0
-	beq _0805B8C4
-	cmp r7, #0x1f
-	bls _0805B848
-_0805B8C4:
-	pop {r3}
-	mov r8, r3
-	pop {r4, r5, r6, r7, pc}
-	.align 2, 0
-	.syntax divided
diff --git a/asm/non_matching/manager21/sub_0805B8CC.inc b/asm/non_matching/manager21/sub_0805B8CC.inc
deleted file mode 100644
index d06a5b37..00000000
--- a/asm/non_matching/manager21/sub_0805B8CC.inc
+++ /dev/null
@@ -1,20 +0,0 @@
-	.syntax unified
-	push {lr}
-	cmp r0, #4
-	bne _0805B8DA
-	movs r0, #0x18
-	bl CheckGlobalFlag
-	b _0805B8E8
-_0805B8DA:
-	cmp r0, #4
-	bls _0805B8E6
-	cmp r0, #6
-	bhi _0805B8E6
-	movs r0, #0
-	b _0805B8E8
-_0805B8E6:
-	movs r0, #1
-_0805B8E8:
-	pop {pc}
-	.align 2, 0
-	.syntax divided
diff --git a/include/flags.h b/include/flags.h
index c68be93e..e6261771 100644
--- a/include/flags.h
+++ b/include/flags.h
@@ -28,7 +28,7 @@ void SetRoomFlag(u32);
 extern u32 gGlobalFlags;
 extern u32 gRoomFlags;
 
-enum {
+typedef enum {
     FLAG_NONE,
     /*0x01*/ LV0_CLEAR,           /*                             */
     /*0x02*/ LV1_CLEAR,           /*                             */
@@ -130,6 +130,6 @@ enum {
     /*0x62*/ MAZE_CLEAR,          /* Cleared Castle maze         */
     /*0x63*/ TINY_ENTRANCE,       /* Ezlo described entrances    */
     /*0x64*/ CASTLE_BGM,          /* Castle intro BGM            */
-};
+} Flags;
 
 #endif
diff --git a/src/manager/manager21.c b/src/manager/manager21.c
index 32c217d4..586fedd6 100644
--- a/src/manager/manager21.c
+++ b/src/manager/manager21.c
@@ -1,6 +1,68 @@
 
 #include "manager.h"
+#include "room.h"
+#include "object.h"
+#include "functions.h"
+#include "flags.h"
 
-ASM_FUNC("asm/non_matching/manager21/Manager21_Main.inc", void Manager21_Main())
+extern bool32 CheckRectOnScreen(u16, u16, u32, u32);
 
-ASM_FUNC("asm/non_matching/manager21/sub_0805B8CC.inc", void sub_0805B8CC())
+typedef struct {
+    Manager manager;
+    u32 field_0x20;
+} Manager21;
+
+typedef struct {
+    u16 x;
+    u16 y;
+    u16 field_0x4;
+    u16 actionDelay;
+} MinishEntranceSpawnData;
+
+bool32 sub_0805B8CC(u32);
+
+/*
+Spawns MINISH_SIZED_ENTRANCE at the locations in the room property this->manager.unk_0a when they are visible on the screen.
+*/
+void Manager21_Main(Manager21* this) {
+    MinishEntranceSpawnData* spawnData;
+    u32 count;
+    if (this->manager.action == 0) {
+        this->manager.action = 1;
+        this->field_0x20 = 0;
+    }
+    spawnData = (MinishEntranceSpawnData*)GetCurrentRoomProperty(this->manager.unk_0a);
+
+    for (count = 0; (spawnData->x != 0) && (count < 0x20); ++count) {
+        if (CheckRectOnScreen(spawnData->x, spawnData->y, 4, 4) != 0) {
+            if (((this->field_0x20 & (1 << count)) == 0) && (sub_0805B8CC(spawnData->field_0x4) != 0)) {
+                Entity* object = CreateObject(MINISH_SIZED_ENTRANCE, 1, 0);
+                if (object != NULL) {
+                    object->actionDelay = spawnData->actionDelay;
+                    object->field_0xf = count;
+                    object->x.HALF.HI = gRoomControls.roomOriginX + spawnData->x;
+                    object->y.HALF.HI = gRoomControls.roomOriginY + spawnData->y;
+                    object->parent = (Entity*)this;
+                    sub_08016A30(object);
+                    this->field_0x20 |= 1 << count;
+                }
+            }
+        } else {
+            this->field_0x20 &= ~(1 << count);
+        }
+        spawnData += 1;
+    }
+}
+
+bool32 sub_0805B8CC(u32 param_1) {
+    if (param_1 == 4) {
+        return CheckGlobalFlag(TATEKAKE_HOUSE);
+    }
+    if (param_1 < 5) {
+        return TRUE;
+    }
+    if (param_1 > 6) {
+        return TRUE;
+    }
+    return FALSE;
+}