diff --git a/lib/comp.c b/lib/comp.c
index c83fcd5..e7f965d 100644
--- a/lib/comp.c
+++ b/lib/comp.c
@@ -4903,7 +4903,7 @@ redo:
 			lit = HCL_ERROR_TO_OOP(oprnd->u.errlit.v);
 			goto literal;
 
-		case HCL_CNODE_SYMBOL:
+		case HCL_CNODE_SYMBOL: /* symbol. but not a literal. usually a variable */
 			if (compile_symbol(hcl, oprnd) <= -1) return -1;
 			goto done;
 
diff --git a/lib/gc.c b/lib/gc.c
index 30dd1eb..9ce31d3 100644
--- a/lib/gc.c
+++ b/lib/gc.c
@@ -298,6 +298,18 @@ static kernel_class_info_t kernel_classes[__KCI_MAX__] =
 		HCL_OFFSETOF(hcl_t, c_string)
 	},
 
+	KCI(KCI_STRING) {
+		"ByteString",
+		KCI_FIXED_SIZED_COLLECTION,
+		HCL_BRAND_BYTE_STRING,
+		0,
+		0,
+		0,
+		HCL_CLASS_SPEC_FLAG_INDEXED,
+		HCL_OBJ_TYPE_BYTE,
+		HCL_OFFSETOF(hcl_t, c_byte_string)
+	},
+
 	KCI(KCI_SYMBOL) {
 		"Symbol",
 		KCI_STRING,
diff --git a/lib/hcl.h b/lib/hcl.h
index ce8dccd..e269cd7 100644
--- a/lib/hcl.h
+++ b/lib/hcl.h
@@ -1713,6 +1713,7 @@ struct hcl_t
 	hcl_oop_class_t c_indexed_collection; /* IndexedCollection */
 	hcl_oop_class_t c_fixed_sized_collection; /* FixedSizedCollection */
 	hcl_oop_class_t c_string; /* String */
+	hcl_oop_class_t c_byte_string; /* String */
 	hcl_oop_class_t c_symbol; /* Symbol */
 	hcl_oop_class_t c_array; /* Array */
 	hcl_oop_class_t c_byte_array; /* ByteArray */
@@ -2007,6 +2008,7 @@ enum hcl_brand_t
 	HCL_BRAND_BYTE_ARRAY,
 	HCL_BRAND_SYMBOL,
 	HCL_BRAND_STRING,
+	HCL_BRAND_BYTE_STRING,
 	HCL_BRAND_DIC,
 	HCL_BRAND_FPDEC, /* fixed-point decimal */
 
diff --git a/lib/obj.c b/lib/obj.c
index b0f182c..cee6efb 100644
--- a/lib/obj.c
+++ b/lib/obj.c
@@ -360,7 +360,7 @@ hcl_oop_t hcl_makebytestringwithbytes (hcl_t* hcl, const hcl_oob_t* ptr, hcl_oow
 	hcl_oow_t i;
 	hcl_oob_t v;
 
-	b = (hcl_oop_byte_t)alloc_numeric_array(hcl, HCL_BRAND_BYTE_ARRAY, ptr, len, HCL_OBJ_TYPE_BYTE, HCL_SIZEOF(hcl_oob_t), 1, ngc);
+	b = (hcl_oop_byte_t)alloc_numeric_array(hcl, HCL_BRAND_BYTE_STRING, ptr, len, HCL_OBJ_TYPE_BYTE, HCL_SIZEOF(hcl_oob_t), 1, ngc);
 	if (HCL_UNLIKELY(!b))
 	{
 		const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
@@ -374,7 +374,7 @@ hcl_oop_t hcl_makebytestringwithbytes (hcl_t* hcl, const hcl_oob_t* ptr, hcl_oow
 			HCL_OBJ_SET_BYTE_VAL(b, i, v);
 		}
 
-		HCL_OBJ_SET_CLASS (b, (hcl_oop_t)hcl->c_byte_array);
+		HCL_OBJ_SET_CLASS (b, (hcl_oop_t)hcl->c_byte_string);
 	}
 
 	return (hcl_oop_t)b;
@@ -391,7 +391,7 @@ hcl_oop_t hcl_makebytestring (hcl_t* hcl, const hcl_ooch_t* ptr, hcl_oow_t len,
 	hcl_oow_t i;
 	hcl_oob_t v;
 
-	b = (hcl_oop_byte_t)alloc_numeric_array(hcl, HCL_BRAND_BYTE_ARRAY, HCL_NULL, len, HCL_OBJ_TYPE_BYTE, HCL_SIZEOF(hcl_oob_t), 1, ngc);
+	b = (hcl_oop_byte_t)alloc_numeric_array(hcl, HCL_BRAND_BYTE_STRING, HCL_NULL, len, HCL_OBJ_TYPE_BYTE, HCL_SIZEOF(hcl_oob_t), 1, ngc);
 	if (HCL_UNLIKELY(!b))
 	{
 		const hcl_ooch_t* orgmsg = hcl_backuperrmsg(hcl);
@@ -405,7 +405,7 @@ hcl_oop_t hcl_makebytestring (hcl_t* hcl, const hcl_ooch_t* ptr, hcl_oow_t len,
 			HCL_OBJ_SET_BYTE_VAL(b, i, v);
 		}
 
-		HCL_OBJ_SET_CLASS (b, (hcl_oop_t)hcl->c_byte_array);
+		HCL_OBJ_SET_CLASS (b, (hcl_oop_t)hcl->c_byte_string);
 	}
 
 	return (hcl_oop_t)b;
diff --git a/lib/print.c b/lib/print.c
index fa39f42..c33d4f0 100644
--- a/lib/print.c
+++ b/lib/print.c
@@ -202,6 +202,69 @@ static HCL_INLINE int print_single_char (hcl_t* hcl, hcl_fmtout_t* fmtout, hcl_o
 	return 0;
 }
 
+static HCL_INLINE int print_single_byte_char (hcl_t* hcl, hcl_fmtout_t* fmtout, hcl_bch_t ch)
+{
+	hcl_bchu_t chu = (hcl_bchu_t)ch;
+	if (chu == '\\' || chu == '\"')
+	{
+		if (hcl_bfmt_out(hcl, fmtout, "\\%hc", chu) <= -1) return -1;
+	}
+#if defined(HCL_OOCH_IS_UCH)
+	else if (chu < ' ')
+#else
+	else if (chu < ' ' || chu >= 0x80)
+#endif
+	{
+		hcl_bchu_t escaped;
+
+		switch (chu)
+		{
+			case '\0':
+				escaped = '0';
+				break;
+			case '\n':
+				escaped = 'n';
+				break;
+			case '\r':
+				escaped = 'r';
+				break;
+			case '\t':
+				escaped = 't';
+				break;
+			case '\f':
+				escaped = 'f';
+				break;
+			case '\b':
+				escaped = 'b';
+				break;
+			case '\v':
+				escaped = 'v';
+				break;
+			case '\a':
+				escaped = 'a';
+				break;
+			default:
+				escaped = chu;
+				break;
+		}
+
+		if (escaped == chu)
+		{
+			if (hcl_bfmt_out(hcl, fmtout, "\\x%02X", chu) <= -1) return -1;
+		}
+		else
+		{
+			if (hcl_bfmt_out(hcl, fmtout, "\\%hc", escaped) <= -1) return -1;
+		}
+	}
+	else
+	{
+		if (hcl_bfmt_out(hcl, fmtout, "%hc", ch) <= -1) return -1;
+	}
+
+	return 0;
+}
+
 int hcl_fmt_object (hcl_t* hcl, hcl_fmtout_t* fmtout, hcl_oop_t obj)
 {
 	hcl_oop_t cur;
@@ -385,7 +448,8 @@ next:
 			 * I simply treat the syntax symbol as a normal symbol
 			 * for printing currently. */
 			/* TODO: escaping if needed */
-			if (hcl_bfmt_out(hcl, fmtout, "#\"%.*js\"", HCL_OBJ_GET_SIZE(obj), HCL_OBJ_GET_CHAR_SLOT(obj)) <= -1) return -1;
+			/*if (hcl_bfmt_out(hcl, fmtout, "#\"%.*js\"", HCL_OBJ_GET_SIZE(obj), HCL_OBJ_GET_CHAR_SLOT(obj)) <= -1) return -1;*/
+			if (hcl_bfmt_out(hcl, fmtout, "%.*js", HCL_OBJ_GET_SIZE(obj), HCL_OBJ_GET_CHAR_SLOT(obj)) <= -1) return -1;
 			break;
 
 		case HCL_BRAND_STRING:
@@ -421,6 +485,40 @@ next:
 			break;
 		}
 
+		case HCL_BRAND_BYTE_STRING:
+		{
+			hcl_bch_t ch;
+			hcl_oow_t i;
+			int escape = 0;
+
+			for (i = 0; i < HCL_OBJ_GET_SIZE(obj); i++)
+			{
+				ch = ((hcl_oop_byte_t)obj)->slot[i];
+				if (ch < ' ' || ch == '\"' || ch == '\\')
+				{
+					escape = 1;
+					break;
+				}
+			}
+
+			if (escape)
+			{
+				if (hcl_bfmt_out(hcl, fmtout, "b\"") <= -1) return -1;
+				for (i = 0; i < HCL_OBJ_GET_SIZE(obj); i++)
+				{
+					ch = ((hcl_oop_byte_t)obj)->slot[i];
+					if (print_single_byte_char(hcl, fmtout, ch) <= -1) return -1;
+				}
+				if (hcl_bfmt_out(hcl, fmtout, "\"") <= -1) return -1;
+			}
+			else
+			{
+				if (hcl_bfmt_out(hcl, fmtout, "b\"%.*hs\"", HCL_OBJ_GET_SIZE(obj), HCL_OBJ_GET_BYTE_SLOT(obj)) <= -1) return -1;
+			}
+			break;
+		}
+
+
 		case HCL_BRAND_CONS:
 		{
 			int concode;