diff --git a/include/m_Do/m_Do_hostIO.h b/include/m_Do/m_Do_hostIO.h
index 25327571d..0c41ebcdd 100644
--- a/include/m_Do/m_Do_hostIO.h
+++ b/include/m_Do/m_Do_hostIO.h
@@ -49,10 +49,10 @@ public:
 
     void update();
     
-    s8 mDoHIO_createChild(const char* name, JORReflexible* hio) {
+    s8 createChild(const char* name, JORReflexible* hio) {
         return m_subroot.createChild(name, hio);
     }
-    void mDoHIO_deleteChild(s8 childID) {
+    void deleteChild(s8 childID) {
         m_subroot.deleteChild(childID);
     }
 
@@ -66,4 +66,12 @@ public:
 
 extern mDoHIO_root_c mDoHIO_root;
 
+inline s8 mDoHIO_createChild(const char* name, JORReflexible* hio) {
+    return mDoHIO_root.createChild(name, hio);
+}
+
+inline void mDoHIO_deleteChild(s8 childID) {
+    mDoHIO_root.deleteChild(childID);
+}
+
 #endif /* M_DO_M_DO_HOSTIO_H */
diff --git a/src/d/actor/d_a_bk.cpp b/src/d/actor/d_a_bk.cpp
index 7403c2f72..c9748b66a 100644
--- a/src/d/actor/d_a_bk.cpp
+++ b/src/d/actor/d_a_bk.cpp
@@ -3086,7 +3086,7 @@ static BOOL daBk_Delete(bk_class* i_this) {
     }
     if (i_this->m121D) {
         hio_set = 0;
-        mDoHIO_root.mDoHIO_deleteChild(l_bkHIO.mChildID);
+        mDoHIO_deleteChild(l_bkHIO.mChildID);
     }
     i_this->m0350.end();
     i_this->dr.mParticleCallBack.end();
@@ -3362,7 +3362,7 @@ static s32 daBk_Create(fopAc_ac_c* i_actor) {
         }
         
         if (!hio_set) {
-            l_bkHIO.mChildID = mDoHIO_root.mDoHIO_createChild("ボコちゃん", &l_bkHIO); // "Boko-chan"
+            l_bkHIO.mChildID = mDoHIO_createChild("ボコちゃん", &l_bkHIO); // "Boko-chan"
             i_this->m121D = 1;
             hio_set = 1;
         }
diff --git a/src/d/actor/d_a_dr.cpp b/src/d/actor/d_a_dr.cpp
index 17c14bba5..c3983afe3 100644
--- a/src/d/actor/d_a_dr.cpp
+++ b/src/d/actor/d_a_dr.cpp
@@ -206,7 +206,7 @@ static BOOL daDr_IsDelete(dr_class* i_this) {
 static BOOL daDr_Delete(dr_class* i_this) {
     dComIfG_resDelete(&i_this->mPhs, "Dr");
     if (l_HIO.mChildID >= 0) {
-        mDoHIO_root.mDoHIO_deleteChild(l_HIO.mChildID);
+        mDoHIO_deleteChild(l_HIO.mChildID);
     }
     return TRUE;
 }
@@ -246,7 +246,7 @@ static s32 daDr_Create(fopAc_ac_c* i_actor) {
         daDr_setMtx(i_this);
         
         if (l_HIO.mChildID < 0) {
-            l_HIO.mChildID = mDoHIO_root.mDoHIO_createChild("ドラゴン", &l_HIO); // "Dragon"
+            l_HIO.mChildID = mDoHIO_createChild("ドラゴン", &l_HIO); // "Dragon"
         }
     }
     
diff --git a/src/d/actor/d_a_mozo.cpp b/src/d/actor/d_a_mozo.cpp
index 5c7ec69c8..5df10c4ff 100644
--- a/src/d/actor/d_a_mozo.cpp
+++ b/src/d/actor/d_a_mozo.cpp
@@ -199,7 +199,7 @@ s32 daMozo_c::CreateInit() {
     wait_proc_init();
 
     if (l_HIO.mChildID < 0) {
-        l_HIO.mChildID = mDoHIO_root.mDoHIO_createChild("モ石像", &l_HIO); // "Mo Statue" (mo sekizou)
+        l_HIO.mChildID = mDoHIO_createChild("モ石像", &l_HIO); // "Mo Statue" (mo sekizou)
     }
 
     return cPhs_COMPLEATE_e;
diff --git a/src/d/actor/d_a_nh.cpp b/src/d/actor/d_a_nh.cpp
index ea981104e..7006f8c13 100644
--- a/src/d/actor/d_a_nh.cpp
+++ b/src/d/actor/d_a_nh.cpp
@@ -75,7 +75,7 @@ daNh_HIO_c::daNh_HIO_c() {
 /* 800F9654-800F9874       .text __dt__6daNh_cFv */
 daNh_c::~daNh_c() {
     if (l_HIO.mChildID >= 0) {
-        mDoHIO_root.mDoHIO_deleteChild(l_HIO.mChildID);
+        mDoHIO_deleteChild(l_HIO.mChildID);
         l_HIO.mChildID = -1;
     }
 }
@@ -135,7 +135,7 @@ s32 daNh_c::create() {
     fopAcM_SetMtx(this, mpModel->getBaseTRMtx());
     
     if (l_HIO.mChildID < 0) {
-        l_HIO.mChildID = mDoHIO_root.mDoHIO_createChild("森のほたる", &l_HIO); // "Forest Firefly" (mori no hotaru)
+        l_HIO.mChildID = mDoHIO_createChild("森のほたる", &l_HIO); // "Forest Firefly" (mori no hotaru)
         l_HIO.mpActor = this;
     }
     if (!init()) {
diff --git a/src/d/actor/d_a_npc_bs1.cpp b/src/d/actor/d_a_npc_bs1.cpp
index 9b5f00d3d..3e1adc258 100644
--- a/src/d/actor/d_a_npc_bs1.cpp
+++ b/src/d/actor/d_a_npc_bs1.cpp
@@ -2102,15 +2102,14 @@ BOOL daNpc_Bs1_c::_delete() {
         mpMorf->stopZelAnime();
     }
     if (l_HIO.m8 >= 0 && (l_HIO.m8 -= 1) < 0) {
-        mDoHIO_root.mDoHIO_deleteChild(l_HIO.mChildId);
+        mDoHIO_deleteChild(l_HIO.mChildId);
     }
     return TRUE;
 }
 
 /* 00004960-00004980       .text CheckCreateHeap__FP10fopAc_ac_c */
 static BOOL CheckCreateHeap(fopAc_ac_c* i_this) {
-    ((daNpc_Bs1_c*)i_this)->CreateHeap();
-    return;
+    return ((daNpc_Bs1_c*)i_this)->CreateHeap();
 }
 
 /* 00004980-00004AD8       .text _create__11daNpc_Bs1_cFv */
@@ -2140,7 +2139,7 @@ s32 daNpc_Bs1_c::_create() {
         } else {
             fopAcM_SetMtx(this, mpMorf->getModel()->getBaseTRMtx());
             if (l_HIO.m8 < 0) {
-                l_HIO.mChildId = mDoHIO_root.mDoHIO_createChild("ボ−トショップ店員", &l_HIO); // "Boat Shopkeeper"
+                l_HIO.mChildId = mDoHIO_createChild("ボ−トショップ店員", &l_HIO); // "Boat Shopkeeper"
             }
             l_HIO.m8 += 1;
             if (!CreateInit()) {
diff --git a/src/d/actor/d_a_npc_kamome.cpp b/src/d/actor/d_a_npc_kamome.cpp
index 9b70bd84b..b729e069e 100644
--- a/src/d/actor/d_a_npc_kamome.cpp
+++ b/src/d/actor/d_a_npc_kamome.cpp
@@ -163,7 +163,7 @@ daNpc_kam_c::~daNpc_kam_c() {
     }
     
     if (l_HIO.mChildID >= 0) {
-        mDoHIO_root.mDoHIO_deleteChild(l_HIO.mChildID);
+        mDoHIO_deleteChild(l_HIO.mChildID);
         l_HIO.mChildID = -1;
     }
     
@@ -268,7 +268,7 @@ s32 daNpc_kam_c::create() {
         fopAcM_SetMtx(this, mpMorf->getModel()->getBaseTRMtx());
         
         if (l_HIO.mChildID < 0) {
-            l_HIO.mChildID = mDoHIO_root.mDoHIO_createChild("かもめ", &l_HIO); // "Seagull" (kamome)
+            l_HIO.mChildID = mDoHIO_createChild("かもめ", &l_HIO); // "Seagull" (kamome)
             l_HIO.mpActor = this;
         }
         
diff --git a/src/d/actor/d_a_npc_md.cpp b/src/d/actor/d_a_npc_md.cpp
index 172ec3389..8cf6de85d 100644
--- a/src/d/actor/d_a_npc_md.cpp
+++ b/src/d/actor/d_a_npc_md.cpp
@@ -456,7 +456,7 @@ s32 daNpc_Md_c::create() {
         fopAcM_SetMtx(this, mpMorf->getModel()->getBaseTRMtx());
         
         if (l_HIO.mChildID < 0) {
-            l_HIO.mChildID = mDoHIO_root.mDoHIO_createChild("リト族（メドリ）", &l_HIO); // "Rito (Medli)" (Ritozoku (Medli))
+            l_HIO.mChildID = mDoHIO_createChild("リト族（メドリ）", &l_HIO); // "Rito (Medli)" (Ritozoku (Medli))
             l_HIO.mpActor = this;
         }
         
@@ -3049,7 +3049,7 @@ daNpc_Md_c::~daNpc_Md_c() {
     m304C.end();
     m3074.remove();
     if (l_HIO.mChildID >= 0) {
-        mDoHIO_root.mDoHIO_deleteChild(l_HIO.mChildID);
+        mDoHIO_deleteChild(l_HIO.mChildID);
         l_HIO.mChildID = -1;
     }
     m_flying = false;
diff --git a/src/d/actor/d_a_npc_os.cpp b/src/d/actor/d_a_npc_os.cpp
index 67fe99b38..28123e84e 100644
--- a/src/d/actor/d_a_npc_os.cpp
+++ b/src/d/actor/d_a_npc_os.cpp
@@ -166,7 +166,7 @@ s32 daNpc_Os_c::create() {
         setBaseMtx();
         fopAcM_SetMtx(this, mpMorf->mpModel->getBaseTRMtx());
         if(l_HIO.field_0x04 < 0) {
-            l_HIO.field_0x04 = mDoHIO_root.mDoHIO_createChild("お供石像", &l_HIO); // "Companion Statue" (otomo sekizou)
+            l_HIO.field_0x04 = mDoHIO_createChild("お供石像", &l_HIO); // "Companion Statue" (otomo sekizou)
             l_HIO.field_0x5C = this;
             l_hio_counter = 1;
         }
@@ -2350,7 +2350,7 @@ daNpc_Os_c::~daNpc_Os_c() {
     }
     
     if(l_hio_counter <= 0 && l_HIO.field_0x04 >= 0) {
-        mDoHIO_root.mDoHIO_deleteChild(l_HIO.field_0x04);
+        mDoHIO_deleteChild(l_HIO.field_0x04);
         l_HIO.field_0x04 = -1;
     }
 
diff --git a/src/d/actor/d_a_obj_quake.cpp b/src/d/actor/d_a_obj_quake.cpp
index d1b14e198..75e7e57d9 100644
--- a/src/d/actor/d_a_obj_quake.cpp
+++ b/src/d/actor/d_a_obj_quake.cpp
@@ -51,7 +51,7 @@ s32 daObjQuake_c::_create() {
         }
 
         if (l_HIO.mChildID < 0) {
-            l_HIO.mChildID = mDoHIO_root.mDoHIO_createChild("振動効果", &l_HIO); // "Vibration Effect"
+            l_HIO.mChildID = mDoHIO_createChild("振動効果", &l_HIO); // "Vibration Effect"
         }
 
         l_HIO.field_0x08 += 1;
@@ -82,7 +82,7 @@ BOOL daObjQuake_c::_is_delete() {
     if (l_HIO.mChildID >= 0) {
         l_HIO.field_0x08 -= 1;
         if (l_HIO.field_0x08 == 0) {
-            mDoHIO_root.mDoHIO_deleteChild(l_HIO.mChildID);
+            mDoHIO_deleteChild(l_HIO.mChildID);
             l_HIO.mChildID = -1;
         }
     }
diff --git a/src/d/actor/d_a_tbox.cpp b/src/d/actor/d_a_tbox.cpp
index 5fb54015c..97d031fc6 100644
--- a/src/d/actor/d_a_tbox.cpp
+++ b/src/d/actor/d_a_tbox.cpp
@@ -537,7 +537,7 @@ void daTbox_c::CreateInit() {
     mAllColRatio = 1.0f;
 
     if (l_HIO.mHioId < 0) {
-        l_HIO.mHioId = mDoHIO_root.mDoHIO_createChild("宝箱", &l_HIO); // "Treasure Chest"
+        l_HIO.mHioId = mDoHIO_createChild("宝箱", &l_HIO); // "Treasure Chest"
     }
 
     shape_angle.z = 0;
@@ -1227,7 +1227,7 @@ static s32 daTbox_Delete(daTbox_c* i_tbox) {
     dComIfG_resDelete(i_tbox->getPhase(), "Dalways");
 
     if (l_HIO.mHioId >= 0) {
-        mDoHIO_root.mDoHIO_deleteChild(l_HIO.mHioId);
+        mDoHIO_deleteChild(l_HIO.mHioId);
         l_HIO.mHioId = -1;
     }
 
diff --git a/src/d/d_menu_option.cpp b/src/d/d_menu_option.cpp
index 76705a250..f42a12f31 100644
--- a/src/d/d_menu_option.cpp
+++ b/src/d/d_menu_option.cpp
@@ -242,7 +242,7 @@ void dMenu_Option_c::_create() {
     mE3A = 0xFF;
     mE3B = 0xC0;
     
-    g_moHIO.mChildID = mDoHIO_root.mDoHIO_createChild("オプション画面", &g_moHIO); // "Option Screen"
+    g_moHIO.mChildID = mDoHIO_createChild("オプション画面", &g_moHIO); // "Option Screen"
 }
 
 /* 801D53F0-801D546C       .text _delete__14dMenu_Option_cFv */
diff --git a/src/d/d_meter.cpp b/src/d/d_meter.cpp
index 8082300a3..80ff26a8d 100644
--- a/src/d/d_meter.cpp
+++ b/src/d/d_meter.cpp
@@ -1883,11 +1883,11 @@ static s32 dMeter_Create(msg_class* i_this) {
     g_dComIfG_gameInfo.play.field_0x4930 = 0;
     g_dComIfG_gameInfo.play.field_0x4931 = 0;
 
-    mDoHIO_root.mDoHIO_createChild("通常画面表示", &g_meterHIO); // "Normal Screen Display"
-    mDoHIO_root.mDoHIO_createChild("メニュー画面", &g_menuHIO); // "Menu Screen"
-    mDoHIO_root.mDoHIO_createChild("Message（会話）", &g_msgHIO); // "Message (Talk)"
-    mDoHIO_root.mDoHIO_createChild("Message（看板）", &g_messageHIO); // "Message (Sign)"
-    mDoHIO_root.mDoHIO_createChild("マップ２", &g_meter_mapHIO); // "Map 2"
+    mDoHIO_createChild("通常画面表示", &g_meterHIO); // "Normal Screen Display"
+    mDoHIO_createChild("メニュー画面", &g_menuHIO); // "Menu Screen"
+    mDoHIO_createChild("Message（会話）", &g_msgHIO); // "Message (Talk)"
+    mDoHIO_createChild("Message（看板）", &g_messageHIO); // "Message (Sign)"
+    mDoHIO_createChild("マップ２", &g_meter_mapHIO); // "Map 2"
 
     dMeter_screenDataSet(i_Meter);
     dMeter_screenDataArrowSet(i_Meter);
diff --git a/src/d/d_s_play.cpp b/src/d/d_s_play.cpp
index ffb4a869e..87c90d2be 100644
--- a/src/d/d_s_play.cpp
+++ b/src/d/d_s_play.cpp
@@ -1110,9 +1110,9 @@ static BOOL dScnPly_Delete(dScnPly_ply_c* i_this) {
     
     g_msgDHIO.field_0x06 = 0;
     g_msgDHIO.field_0x10 = -1;
-    mDoHIO_root.mDoHIO_deleteChild(g_darkHIO.mChildID);
-    mDoHIO_root.mDoHIO_deleteChild(g_envHIO.mChildID);
-    mDoHIO_root.mDoHIO_deleteChild(g_msgDHIO.mChildID);
+    mDoHIO_deleteChild(g_darkHIO.mChildID);
+    mDoHIO_deleteChild(g_envHIO.mChildID);
+    mDoHIO_deleteChild(g_msgDHIO.mChildID);
     
     dComIfGp_setWindowNum(0);
     
@@ -1338,9 +1338,9 @@ s32 phase_4(dScnPly_ply_c* i_this) {
     dStage_Create();
     mDoGph_gInf_c::setTickRate((OS_BUS_CLOCK / 4) / 30);
 
-    g_darkHIO.mChildID = mDoHIO_root.mDoHIO_createChild("暗闇スポット", &g_darkHIO); // "Darkness Spot"
-    g_envHIO.mChildID = mDoHIO_root.mDoHIO_createChild("描画設定", &g_envHIO); // "Draw Settings"
-    g_msgDHIO.mChildID = mDoHIO_root.mDoHIO_createChild("Message Data", &g_msgDHIO);
+    g_darkHIO.mChildID = mDoHIO_createChild("暗闇スポット", &g_darkHIO); // "Darkness Spot"
+    g_envHIO.mChildID = mDoHIO_createChild("描画設定", &g_envHIO); // "Draw Settings"
+    g_msgDHIO.mChildID = mDoHIO_createChild("Message Data", &g_msgDHIO);
 
     new(&dComIfGp_getAttention()) dAttention_c(dComIfGp_getPlayer(0), NULL);
     dComIfGp_getVibration().Init();
diff --git a/src/f_ap/f_ap_game.cpp b/src/f_ap/f_ap_game.cpp
index cdedc6bce..ed73810e7 100644
--- a/src/f_ap/f_ap_game.cpp
+++ b/src/f_ap/f_ap_game.cpp
@@ -98,7 +98,7 @@ void fapGm_Create() {
     fopDwTg_CreateQueue();
     fopScnM_CreateReq(PROC_LOGO_SCENE, PROC_INVALID_e, 0, 0);
 
-    g_HIO.mChildID = mDoHIO_root.mDoHIO_createChild("ゲームシステム", &g_HIO); // "Game System"
+    g_HIO.mChildID = mDoHIO_createChild("ゲームシステム", &g_HIO); // "Game System"
 }
 
 /* 80023288-800232D0       .text __dt__11fapGm_HIO_cFv */