diff --git a/asm/union_room.s b/asm/mystery_gift.s
similarity index 95%
rename from asm/union_room.s
rename to asm/mystery_gift.s
index ca5ad6853..63fd80389 100755
--- a/asm/union_room.s
+++ b/asm/mystery_gift.s
@@ -5,236 +5,6 @@
 
 	.text
 
-	thumb_func_start sub_8018424
-sub_8018424: @ 8018424
-	push {lr}
-	bl ProcessSpriteCopyRequests
-	bl LoadOam
-	bl TransferPlttBuffer
-	pop {r0}
-	bx r0
-	thumb_func_end sub_8018424
-
-	thumb_func_start sub_8018438
-sub_8018438: @ 8018438
-	push {lr}
-	bl RunTasks
-	bl RunTextPrinters
-	bl AnimateSprites
-	bl BuildOamBuffer
-	pop {r0}
-	bx r0
-	thumb_func_end sub_8018438
-
-	thumb_func_start sub_8018450
-sub_8018450: @ 8018450
-	push {r4-r7,lr}
-	sub sp, 0xC
-	adds r7, r0, 0
-	ldr r0, =gMain
-	movs r1, 0x87
-	lsls r1, 3
-	adds r6, r0, r1
-	ldrb r0, [r6]
-	cmp r0, 0x1
-	bne _08018466
-	b _08018574
-_08018466:
-	cmp r0, 0x1
-	bgt _08018474
-	cmp r0, 0
-	beq _08018482
-	b _08018644
-	.pool
-_08018474:
-	cmp r0, 0x2
-	bne _0801847A
-	b _080185F8
-_0801847A:
-	cmp r0, 0x3
-	bne _08018480
-	b _08018618
-_08018480:
-	b _08018644
-_08018482:
-	movs r0, 0
-	bl SetVBlankCallback
-	bl ResetPaletteFade
-	bl ResetSpriteData
-	bl FreeAllSpritePalettes
-	bl ResetTasks
-	bl ScanlineEffect_Stop
-	movs r0, 0
-	bl ResetBgsAndClearDma3BusyFlags
-	ldr r1, =gUnknown_082F0598
-	movs r0, 0
-	movs r2, 0x4
-	bl InitBgsFromTemplates
-	movs r0, 0
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgX
-	movs r0, 0
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgY
-	movs r0, 0x1
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgX
-	movs r0, 0x1
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgY
-	movs r0, 0x2
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgX
-	movs r0, 0x2
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgY
-	movs r0, 0x3
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgX
-	movs r0, 0x3
-	movs r1, 0
-	movs r2, 0
-	bl ChangeBgY
-	movs r4, 0x80
-	lsls r4, 4
-	adds r0, r4, 0
-	bl Alloc
-	adds r1, r0, 0
-	movs r0, 0x3
-	bl SetBgTilemapBuffer
-	adds r0, r4, 0
-	bl Alloc
-	adds r1, r0, 0
-	movs r0, 0x2
-	bl SetBgTilemapBuffer
-	adds r0, r4, 0
-	bl Alloc
-	adds r1, r0, 0
-	movs r0, 0x1
-	bl SetBgTilemapBuffer
-	adds r0, r4, 0
-	bl Alloc
-	adds r1, r0, 0
-	movs r0, 0
-	bl SetBgTilemapBuffer
-	movs r0, 0x3
-	bl bgid_upload_textbox_1
-	ldr r0, =gUnknown_082F05A8
-	bl InitWindows
-	bl DeactivateAllTextPrinters
-	movs r1, 0xC0
-	lsls r1, 7
-	movs r0, 0
-	bl ClearGpuRegBits
-	movs r0, 0x50
-	movs r1, 0
-	bl SetGpuReg
-	movs r0, 0x52
-	movs r1, 0
-	bl SetGpuReg
-	movs r0, 0x54
-	movs r1, 0
-	bl SetGpuReg
-	b _08018610
-	.pool
-_08018574:
-	ldr r0, =gUnkTextboxBorderPal
-	movs r1, 0
-	movs r2, 0x20
-	bl LoadPalette
-	movs r0, 0x2
-	bl stdpal_get
-	movs r1, 0xD0
-	movs r2, 0x20
-	bl LoadPalette
-	movs r0, 0xC0
-	bl sub_81978B0
-	movs r0, 0
-	movs r1, 0xA
-	movs r2, 0xE0
-	bl LoadUserWindowBorderGfx
-	movs r0, 0
-	movs r1, 0x1
-	movs r2, 0xF0
-	bl LoadUserWindowBorderGfx_
-	movs r4, 0x20
-	str r4, [sp]
-	str r4, [sp, 0x4]
-	movs r5, 0x11
-	str r5, [sp, 0x8]
-	movs r0, 0
-	movs r1, 0
-	movs r2, 0
-	movs r3, 0
-	bl FillBgTilemapBufferRect
-	str r4, [sp]
-	str r4, [sp, 0x4]
-	str r5, [sp, 0x8]
-	movs r0, 0x1
-	movs r1, 0
-	movs r2, 0
-	movs r3, 0
-	bl FillBgTilemapBufferRect
-	str r4, [sp]
-	str r4, [sp, 0x4]
-	str r5, [sp, 0x8]
-	movs r0, 0x2
-	movs r1, 0
-	movs r2, 0
-	movs r3, 0
-	bl FillBgTilemapBufferRect
-	movs r0, 0x3
-	bl sub_8018798
-	lsls r0, r7, 24
-	lsrs r0, 24
-	movs r1, 0
-	bl sub_80186EC
-	b _08018610
-	.pool
-_080185F8:
-	movs r0, 0x3
-	bl CopyBgTilemapBufferToVram
-	movs r0, 0x2
-	bl CopyBgTilemapBufferToVram
-	movs r0, 0x1
-	bl CopyBgTilemapBufferToVram
-	movs r0, 0
-	bl CopyBgTilemapBufferToVram
-_08018610:
-	ldrb r0, [r6]
-	adds r0, 0x1
-	strb r0, [r6]
-	b _08018644
-_08018618:
-	movs r0, 0
-	bl ShowBg
-	movs r0, 0x3
-	bl ShowBg
-	ldr r0, =0x0000021d
-	bl PlayBGM
-	ldr r0, =sub_8018424
-	bl SetVBlankCallback
-	movs r0, 0xC5
-	bl EnableInterrupts
-	movs r0, 0x1
-	b _08018646
-	.pool
-_08018644:
-	movs r0, 0
-_08018646:
-	add sp, 0xC
-	pop {r4-r7}
-	pop {r1}
-	bx r1
-	thumb_func_end sub_8018450
-
 	thumb_func_start c2_mystery_gift
 c2_mystery_gift: @ 8018650
 	push {lr}
diff --git a/data/union_room.s b/data/mystery_gift.s
similarity index 78%
rename from data/union_room.s
rename to data/mystery_gift.s
index 6934f0fd8..cfca73479 100755
--- a/data/union_room.s
+++ b/data/mystery_gift.s
@@ -3,60 +3,6 @@
 
 	.section .rodata
 
-	.align 2
-gUnkTextboxBorderPal:: @ 82F0548
-	.incbin "graphics/interface/unk_textbox_border.gbapal"
-
-	.align 2
-gUnkTextboxBorderGfx:: @ 82F0568
-	.incbin "graphics/interface/unk_textbox_border.4bpp.lz"
-
-	.align 2
-gUnknown_082F0598:: @ 82F0598 struct BgTemplate
-	.4byte 0x000000f8
-	.4byte 0x000010e1
-	.4byte 0x000020d2
-	.4byte 0x000030c3
-
-	.align 2
-gUnknown_082F05A8:: @ 82F05A8
-	window_template 0x00, 0x00, 0x00, 0x1e, 0x02, 0x0c, 0x0013
-	window_template 0x00, 0x01, 0x0f, 0x1c, 0x04, 0x0c, 0x004f
-	window_template 0x00, 0x00, 0x0f, 0x1e, 0x05, 0x0d, 0x004f
-	null_window_template
-
-	.align 2
-gUnknown_082F05C8:: @ 82F05C8
-	window_template 0x00, 0x01, 0x0f, 0x1c, 0x04, 0x0c, 0x00e5
-
-	.align 2
-gUnknown_082F05D0:: @ 82F05D0
-	window_template 0x00, 0x01, 0x0f, 0x14, 0x04, 0x0c, 0x00e5
-
-	.align 2
-gUnknown_082F05D8:: @ 82F05D8
-	window_template 0x00, 0x01, 0x0f, 0x13, 0x04, 0x0c, 0x00e5
-
-	.align 2
-gUnknown_082F05E0:: @ 82F05E0
-	window_template 0x00, 0x08, 0x06, 0x0e, 0x06, 0x0c, 0x0155
-
-	.align 2
-gUnknown_082F05E8:: @ 82F05E8
-	window_template 0x00, 0x17, 0x0f, 0x06, 0x04, 0x0c, 0x0155
-
-	.align 2
-gUnknown_082F05F0:: @ 82F05F0
-	window_template 0x00, 0x16, 0x0b, 0x07, 0x08, 0x0c, 0x0155
-
-	.align 2
-gUnknown_082F05F8:: @ 82F05F8
-	window_template 0x00, 0x16, 0x0d, 0x07, 0x06, 0x0c, 0x0155
-
-	.align 2
-gUnknown_082F0600:: @ 82F0600
-	window_template 0x00, 0x16, 0x0f, 0x07, 0x04, 0x0c, 0x0155
-
 	.align 2
 gUnknown_082F0608:: @ 82F0608
 	.4byte gText_WonderCards, 0x00000000
diff --git a/include/mystery_gift.h b/include/mystery_gift.h
new file mode 100644
index 000000000..b83239bc7
--- /dev/null
+++ b/include/mystery_gift.h
@@ -0,0 +1,4 @@
+#ifndef GUARD_MYSTERY_GIFT_H
+#define GUARD_MYSTERY_GIFT_H
+
+#endif //GUARD_MYSTERY_GIFT_H
diff --git a/ld_script.txt b/ld_script.txt
index 746fd4bd0..4f4bc55d7 100644
--- a/ld_script.txt
+++ b/ld_script.txt
@@ -55,7 +55,8 @@ SECTIONS {
         src/link.o(.text);
         src/link_rfu.o(.text);
         src/union_room.o(.text);
-        asm/union_room.o(.text);
+        src/mystery_gift.o(.text);
+        asm/mystery_gift.o(.text);
         src/mevent2.o(.text);
         src/mevent_801BAAC.o(.text);
         asm/mevent_server.o(.text);
@@ -409,7 +410,8 @@ SECTIONS {
         src/link.o(.rodata);
         src/link_rfu.o(.rodata);
         src/union_room.o(.rodata);
-        data/union_room.o(.rodata);
+        src/mystery_gift.o(.rodata);
+        data/mystery_gift.o(.rodata);
         src/mevent2.o(.rodata);
         src/mevent_801BAAC.o(.rodata);
         data/mevent_server.o(.rodata);
diff --git a/src/mystery_gift.c b/src/mystery_gift.c
new file mode 100644
index 000000000..b6c317281
--- /dev/null
+++ b/src/mystery_gift.c
@@ -0,0 +1,253 @@
+#include "global.h"
+#include "main.h"
+#include "text.h"
+#include "task.h"
+#include "alloc.h"
+#include "gpu_regs.h"
+#include "scanline_effect.h"
+#include "text_window.h"
+#include "bg.h"
+#include "window.h"
+#include "text_window.h"
+#include "menu.h"
+#include "palette.h"
+#include "constants/songs.h"
+#include "sound.h"
+#include "mystery_gift.h"
+
+void bgid_upload_textbox_1(u8 bgId);
+void sub_8018798(u8);
+void sub_80186EC(u8, u8);
+
+const u16 gUnkTextboxBorderPal[] = INCBIN_U16("graphics/interface/unk_textbox_border.gbapal");
+const u32 gUnkTextboxBorderGfx[] = INCBIN_U32("graphics/interface/unk_textbox_border.4bpp.lz");
+
+const struct BgTemplate gUnknown_082F0598[] = {
+    {
+        .bg = 0,
+        .charBaseIndex = 2,
+        .mapBaseIndex = 15,
+        .screenSize = 0,
+        .paletteMode = 0,
+        .priority = 0,
+        .baseTile = 0x000
+    }, {
+        .bg = 1,
+        .charBaseIndex = 0,
+        .mapBaseIndex = 14,
+        .screenSize = 0,
+        .paletteMode = 0,
+        .priority = 1,
+        .baseTile = 0x000
+    }, {
+        .bg = 2,
+        .charBaseIndex = 0,
+        .mapBaseIndex = 13,
+        .screenSize = 0,
+        .paletteMode = 0,
+        .priority = 2,
+        .baseTile = 0x000
+    }, {
+        .bg = 3,
+        .charBaseIndex = 0,
+        .mapBaseIndex = 12,
+        .screenSize = 0,
+        .paletteMode = 0,
+        .priority = 3,
+        .baseTile = 0x000
+    }
+};
+
+const struct WindowTemplate gUnknown_082F05A8[] = {
+    {
+        .bg = 0x00,
+        .tilemapLeft = 0x00,
+        .tilemapTop = 0x00,
+        .width = 0x1e,
+        .height = 0x02,
+        .paletteNum = 0x0c,
+        .baseBlock = 0x0013
+    }, {
+        .bg = 0x00,
+        .tilemapLeft = 0x01,
+        .tilemapTop = 0x0f,
+        .width = 0x1c,
+        .height = 0x04,
+        .paletteNum = 0x0c,
+        .baseBlock = 0x004f
+    }, {
+        .bg = 0x00,
+        .tilemapLeft = 0x00,
+        .tilemapTop = 0x0f,
+        .width = 0x1e,
+        .height = 0x05,
+        .paletteNum = 0x0d,
+        .baseBlock = 0x004f
+    }, {
+        0xFF
+    }
+};
+
+const struct WindowTemplate gUnknown_082F05C8 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x01,
+    .tilemapTop = 0x0f,
+    .width = 0x1c,
+    .height = 0x04,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x00e5
+};
+
+const struct WindowTemplate gUnknown_082F05D0 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x01,
+    .tilemapTop = 0x0f,
+    .width = 0x14,
+    .height = 0x04,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x00e5
+};
+
+const struct WindowTemplate gUnknown_082F05D8 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x01,
+    .tilemapTop = 0x0f,
+    .width = 0x13,
+    .height = 0x04,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x00e5
+};
+
+const struct WindowTemplate gUnknown_082F05E0 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x08,
+    .tilemapTop = 0x06,
+    .width = 0x0e,
+    .height = 0x06,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x0155
+};
+
+const struct WindowTemplate gUnknown_082F05E8 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x17,
+    .tilemapTop = 0x0f,
+    .width = 0x06,
+    .height = 0x04,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x0155
+};
+
+const struct WindowTemplate gUnknown_082F05F0 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x16,
+    .tilemapTop = 0x0b,
+    .width = 0x07,
+    .height = 0x08,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x0155
+};
+
+const struct WindowTemplate gUnknown_082F05F8 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x16,
+    .tilemapTop = 0x0d,
+    .width = 0x07,
+    .height = 0x06,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x0155
+};
+
+const struct WindowTemplate gUnknown_082F0600 = {
+    .bg = 0x00,
+    .tilemapLeft = 0x16,
+    .tilemapTop = 0x0f,
+    .width = 0x07,
+    .height = 0x04,
+    .paletteNum = 0x0c,
+    .baseBlock = 0x0155
+};
+
+void sub_8018424(void)
+{
+    ProcessSpriteCopyRequests();
+    LoadOam();
+    TransferPlttBuffer();
+}
+
+void sub_8018438(void)
+{
+    RunTasks();
+    RunTextPrinters();
+    AnimateSprites();
+    BuildOamBuffer();
+}
+
+bool32 sub_8018450(s32 arg)
+{
+    switch (gMain.state)
+    {
+    case 0:
+        SetVBlankCallback(NULL);
+        ResetPaletteFade();
+        ResetSpriteData();
+        FreeAllSpritePalettes();
+        ResetTasks();
+        ScanlineEffect_Stop();
+        ResetBgsAndClearDma3BusyFlags(0);
+
+        InitBgsFromTemplates(0, gUnknown_082F0598, ARRAY_COUNT(gUnknown_082F0598));
+        ChangeBgX(0, 0, 0);
+        ChangeBgY(0, 0, 0);
+        ChangeBgX(1, 0, 0);
+        ChangeBgY(1, 0, 0);
+        ChangeBgX(2, 0, 0);
+        ChangeBgY(2, 0, 0);
+        ChangeBgX(3, 0, 0);
+        ChangeBgY(3, 0, 0);
+
+        SetBgTilemapBuffer(3, Alloc(0x800));
+        SetBgTilemapBuffer(2, Alloc(0x800));
+        SetBgTilemapBuffer(1, Alloc(0x800));
+        SetBgTilemapBuffer(0, Alloc(0x800));
+
+        bgid_upload_textbox_1(3);
+        InitWindows(gUnknown_082F05A8);
+        DeactivateAllTextPrinters();
+        ClearGpuRegBits(REG_OFFSET_DISPCNT, DISPCNT_WIN0_ON | DISPCNT_WIN1_ON);
+        SetGpuReg(REG_OFFSET_BLDCNT, 0);
+        SetGpuReg(REG_OFFSET_BLDALPHA, 0);
+        SetGpuReg(REG_OFFSET_BLDY, 0);
+        gMain.state++;
+        break;
+    case 1:
+        LoadPalette(gUnkTextboxBorderPal, 0, 0x20);
+        LoadPalette(stdpal_get(2), 0xd0, 0x20);
+        sub_81978B0(0xC0);
+        LoadUserWindowBorderGfx(0, 0xA, 0xE0);
+        LoadUserWindowBorderGfx_(0, 0x1, 0xF0);
+        FillBgTilemapBufferRect(0, 0x000, 0, 0, 32, 32, 0x11);
+        FillBgTilemapBufferRect(1, 0x000, 0, 0, 32, 32, 0x11);
+        FillBgTilemapBufferRect(2, 0x000, 0, 0, 32, 32, 0x11);
+        sub_8018798(3);
+        sub_80186EC(arg, 0);
+        gMain.state++;
+        break;
+    case 2:
+        CopyBgTilemapBufferToVram(3);
+        CopyBgTilemapBufferToVram(2);
+        CopyBgTilemapBufferToVram(1);
+        CopyBgTilemapBufferToVram(0);
+        gMain.state++;
+        break;
+    case 3:
+        ShowBg(0);
+        ShowBg(3);
+        PlayBGM(MUS_RG_OKURIMONO);
+        SetVBlankCallback(sub_8018424);
+        EnableInterrupts(INTR_FLAG_VBLANK | INTR_FLAG_VCOUNT | INTR_FLAG_TIMER3 | INTR_FLAG_SERIAL);
+        return TRUE;
+    }
+
+    return FALSE;
+}