diff --git a/src/sys/nact.cpp b/src/sys/nact.cpp
index fb11295..8ff84f5 100644
--- a/src/sys/nact.cpp
+++ b/src/sys/nact.cpp
@@ -423,14 +423,8 @@ void NACT::cmd_a()
 		sys_sleep(16);
 	}
 	sys_sleep(30);
-	while (!msgskip->skipping()) {
-		if(terminate) {
-			return;
-		}
-		if(!(get_key() & 0x18)) {
-			break;
-		}
-		sys_sleep(16);
+	if (!msgskip->skipping()) {
+		wait_key_release(0x18);
 	}
 
 	// ウィンドウ更新
@@ -653,15 +647,7 @@ int NACT::menu_select(int num_items)
 			sys_sleep(16);
 		}
 		if(val) {
-			for(;;) {
-				if(terminate) {
-					return -1;
-				}
-				if(!get_key()) {
-					break;
-				}
-				sys_sleep(16);
-			}
+			wait_key_release();
 		}
 
 		if(val == 0) {
@@ -729,16 +715,7 @@ void NACT::wait_after_open_menu()
 		}
 	}
 
-	// クリック中の間は待機
-	for(;;) {
-		if(terminate) {
-			return;
-		}
-		if(!get_key()) {
-			break;
-		}
-		sys_sleep(10);
-	}
+	wait_key_release();
 }
 
 void NACT::sys_sleep(int ms) {
diff --git a/src/sys/nact.h b/src/sys/nact.h
index d73fd0d..cc159bb 100644
--- a/src/sys/nact.h
+++ b/src/sys/nact.h
@@ -147,6 +147,8 @@ protected:
 	void wait_after_open_menu();
 
 	uint8 get_key();
+	void wait_key_release(uint8_t mask = 0xff);
+
 	void get_cursor(int* x, int* y);
 	void set_cursor(int x, int y);
 	int get_wheel();
diff --git a/src/sys/nact_input.cpp b/src/sys/nact_input.cpp
index 8c95d7c..154e74a 100644
--- a/src/sys/nact_input.cpp
+++ b/src/sys/nact_input.cpp
@@ -143,6 +143,11 @@ uint8 NACT::get_key()
 	return val;
 }
 
+void NACT::wait_key_release(uint8_t mask) {
+	while (!terminate && (get_key() & mask))
+		sys_sleep(16);
+}
+
 void NACT::get_cursor(int* x, int* y)
 {
 	pump_events();
diff --git a/src/sys/nact_sys1.cpp b/src/sys/nact_sys1.cpp
index ff905ae..6bf9768 100644
--- a/src/sys/nact_sys1.cpp
+++ b/src/sys/nact_sys1.cpp
@@ -744,15 +744,7 @@ public:
 				sys_sleep(16);
 			}
 			sys_sleep(100);
-			for (;;) {
-				if (terminate) {
-					return;
-				}
-				if (!(get_key() & 0x18)) {
-					break;
-				}
-				sys_sleep(16);
-			}
+			wait_key_release(0x18);
 			ags->clear_text_window(text_window, true);
 			break;
 		case 2:
diff --git a/src/sys/nact_sys2.cpp b/src/sys/nact_sys2.cpp
index c5407dc..c3b656a 100644
--- a/src/sys/nact_sys2.cpp
+++ b/src/sys/nact_sys2.cpp
@@ -805,15 +805,7 @@ void NACT_Sys2::cmd_y()
 				sys_sleep(16);
 			}
 			sys_sleep(100);
-			for(;;) {
-				if(terminate) {
-					return;
-				}
-				if(!(get_key() & 0x18)) {
-					break;
-				}
-				sys_sleep(16);
-			}
+			wait_key_release(0x18);
 			break;
 		case 254:
 			RND = 0;
diff --git a/src/sys/nact_sys3.cpp b/src/sys/nact_sys3.cpp
index d160f69..e727e8a 100644
--- a/src/sys/nact_sys3.cpp
+++ b/src/sys/nact_sys3.cpp
@@ -452,15 +452,7 @@ void NACT_Sys3::cmd_k()
 	// キーが離されるまで待機
 	if(cmd != 1) {
 		sys_sleep(100);
-		for(;;) {
-			if(terminate) {
-				return;
-			}
-			if(!(val = get_key())) {
-				break;
-			}
-			sys_sleep(16);
-		}
+		wait_key_release();
 	}
 
 	// K0の場合は改行
@@ -884,16 +876,7 @@ void NACT_Sys3::exec_y(int cmd, int param)
 				M_X = (x < 0) ? x : (x > 639) ? 639 : x;
 				M_Y = (y < 0) ? 0 : (y > 479) ? 479 : y;
 				if((RND = get_key())) {
-					// キー入力があった場合は、離すまで待機
-					for(;;) {
-						if(terminate) {
-							return;
-						}
-						if(!get_key()) {
-							break;
-						}
-						sys_sleep(16);
-					}
+					wait_key_release();
 				}
 			} else if(param == 3) {
 				set_cursor(M_X, M_Y);
@@ -1310,9 +1293,7 @@ bool NACT_Sys3::k3_hack(const K3HackInfo* info_table)
 		}
 		int key = get_key();
 		if (key) {
-			// Wait for key release
-			while (!terminate && get_key())
-				sys_sleep(16);
+			wait_key_release();
 			RND = key;
 			break;
 		}
@@ -1442,11 +1423,6 @@ private:
 	uint16_t grid_select_data[63] = {};
 	uint16_t grid_prev_selection = 0;
 
-	void wait_key_release() {
-		while (!terminate && get_key())
-			sys_sleep(16);
-	}
-
 	// I command
 	uint16_t grid_select(int left_x, int top_y, int xsize, int ysize, int nr_cols, int nr_rows, int initial_index) {
 		int x = initial_index % nr_cols;