diff --git a/src/encoding-convert.js b/src/encoding-convert.js
index a7722d0..bcdd154 100644
--- a/src/encoding-convert.js
+++ b/src/encoding-convert.js
@@ -154,6 +154,17 @@ function SJISToJIS(data) {
       }
       results[results.length] = b1 - 0x80 & 0xFF;
     } else if (b1 >= 0x80) {
+      b2 = data[++i];
+      if (b2 === 0x7F) {
+        if (index !== 0) {
+          index = 0;
+          results[results.length] = esc[0];
+          results[results.length] = esc[1];
+          results[results.length] = esc[2];
+        }
+        results[results.length] = config.FALLBACK_CHARACTER;
+        continue;
+      }
       if (index !== 1) {
         index = 1;
         results[results.length] = esc[3];
@@ -161,7 +172,6 @@ function SJISToJIS(data) {
         results[results.length] = esc[5];
       }
 
-      b2 = data[++i];
       if (sjisExt.hasCP932DuplicateCode(b1)) {
         // Remap CP932 duplicate codes and IBM extended characters
         remapped = sjisExt.remapCP932DuplicateCode(b1, b2);
@@ -228,6 +238,10 @@ function SJISToEUCJP(data) {
       results[results.length] = b1;
     } else if (b1 >= 0x81) {
       b2 = data[++i];
+      if (b2 === 0x7F) {
+        results[results.length] = config.FALLBACK_CHARACTER;
+        continue;
+      }
       if (sjisExt.hasCP932DuplicateCode(b1)) {
         // Remap CP932 duplicate codes and IBM extended characters
         remapped = sjisExt.remapCP932DuplicateCode(b1, b2);
@@ -409,6 +423,10 @@ function SJISToUTF8(data) {
       results[results.length] = u3 & 0xFF;
     } else if (b >= 0x80) {
       b2 = data[++i];
+      if (b2 === 0x7F) {
+        results[results.length] = config.FALLBACK_CHARACTER;
+        continue;
+      }
       if (sjisExt.hasCP932DuplicateCode(b)) {
         // Remap CP932 duplicate codes and IBM extended characters
         remapped = sjisExt.remapCP932DuplicateCode(b, b2);
@@ -642,7 +660,8 @@ function UTF8ToSJIS(data, options) {
                (data[++i] & 0xFF);
       }
 
-      jis = EncodingTable.UTF8_TO_JIS_TABLE[utf8];
+      jis = EncodingTable.UTF8_TO_JIS_TABLE[utf8] ||
+        EncodingTable.UTF8_TO_JIS_ALIAS_TABLE[utf8];
       if (jis == null) {
         if (fallbackOption) {
           handleFallback(results, bytes, fallbackOption);
@@ -653,10 +672,6 @@ function UTF8ToSJIS(data, options) {
         if (jis < 0xFF) {
           results[results.length] = jis + 0x80;
         } else {
-          if (jis > 0x10000) {
-            jis -= 0x10000;
-          }
-
           b1 = jis >> 8;
           b2 = jis & 0xFF;
           if (b1 & 0x01) {
@@ -701,7 +716,7 @@ function UTF8ToEUCJP(data, options) {
   var results = [];
   var i = 0;
   var len = data && data.length;
-  var b, bytes, utf8, jis;
+  var b, bytes, utf8, jis, isJISX0212;
   var fallbackOption = options && options.fallback;
 
   for (; i < len; i++) {
@@ -726,32 +741,28 @@ function UTF8ToEUCJP(data, options) {
                (data[++i] & 0xFF);
       }
 
-      jis = EncodingTable.UTF8_TO_JIS_TABLE[utf8];
       // JIS X 0212 chars duplicated into JIS X 0208 unassigned rows: use the JIS X 0212 form.
-      if (jis != null && EncodingTable.UTF8_TO_JISX0212_TABLE[utf8] != null) {
-        jis = null;
+      jis = EncodingTable.UTF8_TO_JISX0212_TABLE[utf8];
+      isJISX0212 = jis != null;
+
+      if (jis == null) {
+        jis = EncodingTable.UTF8_TO_JIS_TABLE[utf8] ||
+          EncodingTable.UTF8_TO_JIS_ALIAS_TABLE[utf8];
       }
       if (jis == null) {
-        jis = EncodingTable.UTF8_TO_JISX0212_TABLE[utf8];
-        if (jis == null) {
-          if (fallbackOption) {
-            handleFallback(results, bytes, fallbackOption);
-          } else {
-            results[results.length] = config.FALLBACK_CHARACTER;
-          }
+        if (fallbackOption) {
+          handleFallback(results, bytes, fallbackOption);
         } else {
-          results[results.length] = 0x8F;
-          results[results.length] = (jis >> 8) - 0x80 & 0xFF;
-          results[results.length] = (jis & 0xFF) - 0x80 & 0xFF;
+          results[results.length] = config.FALLBACK_CHARACTER;
         }
       } else {
-        if (jis > 0x10000) {
-          jis -= 0x10000;
-        }
         if (jis < 0xFF) {
           results[results.length] = 0x8E;
           results[results.length] = jis - 0x80 & 0xFF;
         } else {
+          if (isJISX0212) {
+            results[results.length] = 0x8F;
+          }
           results[results.length] = (jis >> 8) - 0x80 & 0xFF;
           results[results.length] = (jis & 0xFF) - 0x80 & 0xFF;
         }
@@ -773,7 +784,7 @@ function UTF8ToJIS(data, options) {
   var index = 0;
   var len = data && data.length;
   var i = 0;
-  var b, bytes, utf8, jis;
+  var b, bytes, utf8, jis, isJISX0212;
   var fallbackOption = options && options.fallback;
 
   var esc = [
@@ -813,42 +824,29 @@ function UTF8ToJIS(data, options) {
                (data[++i] & 0xFF);
       }
 
-      jis = EncodingTable.UTF8_TO_JIS_TABLE[utf8];
       // JIS X 0212 chars duplicated into JIS X 0208 unassigned rows: use the JIS X 0212 form.
-      if (jis != null && EncodingTable.UTF8_TO_JISX0212_TABLE[utf8] != null) {
-        jis = null;
+      jis = EncodingTable.UTF8_TO_JISX0212_TABLE[utf8];
+      isJISX0212 = jis != null;
+
+      if (jis == null) {
+        jis = EncodingTable.UTF8_TO_JIS_TABLE[utf8] ||
+          EncodingTable.UTF8_TO_JIS_ALIAS_TABLE[utf8];
       }
+
       if (jis == null) {
-        jis = EncodingTable.UTF8_TO_JISX0212_TABLE[utf8];
-        if (jis == null) {
-          if (index !== 0) {
-            index = 0;
-            results[results.length] = esc[0];
-            results[results.length] = esc[1];
-            results[results.length] = esc[2];
-          }
+        if (index !== 0) {
+          index = 0;
+          results[results.length] = esc[0];
+          results[results.length] = esc[1];
+          results[results.length] = esc[2];
+        }
 
-          if (fallbackOption) {
-            handleFallback(results, bytes, fallbackOption);
-          } else {
-            results[results.length] = config.FALLBACK_CHARACTER;
-          }
+        if (fallbackOption) {
+          handleFallback(results, bytes, fallbackOption);
         } else {
-          // JIS X 0212:1990
-          if (index !== 3) {
-            index = 3;
-            results[results.length] = esc[9];
-            results[results.length] = esc[10];
-            results[results.length] = esc[11];
-            results[results.length] = esc[12];
-          }
-          results[results.length] = jis >> 8 & 0xFF;
-          results[results.length] = jis & 0xFF;
+          results[results.length] = config.FALLBACK_CHARACTER;
         }
       } else {
-        if (jis > 0x10000) {
-          jis -= 0x10000;
-        }
         if (jis < 0xFF) {
           // Halfwidth Katakana
           if (index !== 2) {
@@ -859,7 +857,17 @@ function UTF8ToJIS(data, options) {
           }
           results[results.length] = jis & 0xFF;
         } else {
-          if (index !== 1) {
+          if (isJISX0212) {
+            // JIS X 0212:1990
+            if (index !== 3) {
+              index = 3;
+              results[results.length] = esc[9];
+              results[results.length] = esc[10];
+              results[results.length] = esc[11];
+              results[results.length] = esc[12];
+            }
+          } else if (index !== 1) {
+            // JIS X 0208
             index = 1;
             results[results.length] = esc[3];
             results[results.length] = esc[4];
@@ -933,8 +941,9 @@ function UTF8ToUNICODE(data, options) {
   var i = 0;
   var len = data && data.length;
   var n, c, c2, c3, c4, code;
-  // For internal usage only
-  var ignoreSurrogatePair = options && options.ignoreSurrogatePair;
+  // For internal use only
+  // Returns raw Unicode code points without splitting into surrogate pairs
+  var asCodePoint = options && options.asCodePoint;
 
   while (i < len) {
     c = data[i++];
@@ -970,7 +979,7 @@ function UTF8ToUNICODE(data, options) {
               (c4 & 0x3F);
     }
 
-    if (code <= 0xFFFF || ignoreSurrogatePair) {
+    if (code <= 0xFFFF || asCodePoint) {
       results[results.length] = code;
     } else {
       // Split in surrogate halves
@@ -1685,7 +1694,7 @@ function handleFallback(results, bytes, fallbackOption) {
   switch (fallbackOption) {
     case 'html-entity':
     case 'html-entity-hex':
-      var unicode = UTF8ToUNICODE(bytes, { ignoreSurrogatePair: true })[0];
+      var unicode = UTF8ToUNICODE(bytes, { asCodePoint: true })[0];
       if (unicode) {
         results[results.length] = 0x26; // &
         results[results.length] = 0x23; // #
diff --git a/src/encoding-table.js b/src/encoding-table.js
index 44de98c..8823e8c 100644
--- a/src/encoding-table.js
+++ b/src/encoding-table.js
@@ -1,4 +1,5 @@
 exports.UTF8_TO_JIS_TABLE = require('./utf8-to-jis-table');
+exports.UTF8_TO_JIS_ALIAS_TABLE = require('./utf8-to-jis-alias-table');
 exports.UTF8_TO_JISX0212_TABLE = require('./utf8-to-jisx0212-table');
 exports.JIS_TO_UTF8_TABLE = require('./jis-to-utf8-table');
 exports.JISX0212_TO_UTF8_TABLE = require('./jisx0212-to-utf8-table');
diff --git a/src/utf8-to-jis-alias-table.js b/src/utf8-to-jis-alias-table.js
new file mode 100644
index 0000000..98b4fb4
--- /dev/null
+++ b/src/utf8-to-jis-alias-table.js
@@ -0,0 +1,14 @@
+/**
+ * Encoding conversion table for UTF-8 to JIS (encode only)
+ *
+ * Accepts Unicode characters that differ between CP932 and JIS X 0208 mappings
+ * (e.g., WAVE DASH vs. FULLWIDTH TILDE).
+ *
+ * { UTF-8 : JIS }
+ */
+module.exports = {
+  0xE28892: 0x215D, // − U+2212 MINUS SIGN same cell as － U+FF0D (0xEFBC8D) -> SJIS 0x817C
+  0xE3809C: 0x2141, // 〜 U+301C WAVE DASH same cell as ～ U+FF5E (0xEFBD9E) -> SJIS 0x8160
+  0xC2A2: 0x2171,   // ¢ U+00A2 CENT SIGN  same cell as ￠ U+FFE0 (0xEFBFA0) -> SJIS 0x8191
+  0xC2A3: 0x2172    // £ U+00A3 POUND SIGN same cell as ￡ U+FFE1 (0xEFBFA1) -> SJIS 0x8192
+};
diff --git a/src/utf8-to-jis-table.js b/src/utf8-to-jis-table.js
index cfc8d05..b25c292 100644
--- a/src/utf8-to-jis-table.js
+++ b/src/utf8-to-jis-table.js
@@ -1,6 +1,7 @@
 /* eslint-disable @stylistic/indent, @stylistic/key-spacing */
 /**
  * Encoding conversion table for UTF-8 to JIS
+ * { UTF-8 : JIS }
  */
 module.exports = {
 0xEFBDA1:0x21,0xEFBDA2:0x22,0xEFBDA3:0x23,0xEFBDA4:0x24,0xEFBDA5:0x25,
@@ -1486,8 +1487,8 @@ module.exports = {
 0xE285B5:0x7C76,0xE285B6:0x7C77,0xE285B7:0x7C78,0xE285B8:0x7C79,0xE285B9:0x7C7A,
 0xEFBFA4:0x7C7C,0xEFBC87:0x7C7D,0xEFBC82:0x7C7E,
 
-//FIXME: mojibake
-0xE288A5:0x2142,
-0xEFBFA2:0x224C,
-0xE28892:0x1215D
+// Remaps Unicode characters that differ between CP932 and JIS X 0208 mappings
+// (encode and decode) See also `utf8-to-jis-alias-table.js`
+0xE288A5:0x2142, // ∥ U+2225 PARALLEL TO        same cell as ‖ U+2016 (0xE28096) -> SJIS 0x8161
+0xEFBFA2:0x224C  // ￢ U+FFE2 FULLWIDTH NOT SIGN same cell as ¬ U+00AC (0xC2AC)   -> SJIS 0x81CA
 };
diff --git a/src/utf8-to-jisx0212-table.js b/src/utf8-to-jisx0212-table.js
index 3043199..dd1a329 100644
--- a/src/utf8-to-jisx0212-table.js
+++ b/src/utf8-to-jisx0212-table.js
@@ -1,6 +1,11 @@
 /* eslint-disable @stylistic/indent,@stylistic/key-spacing */
 /**
  * Encoding conversion table for UTF-8 to JIS X 0212:1990 (Hojo-Kanji)
+ *
+ * Character mappings based on:
+ * https://www.unicode.org/Public/MAPPINGS/OBSOLETE/EASTASIA/JIS/JIS0212.TXT
+ * Keys have been converted to UTF-8
+ * { UTF-8 : JIS }
  */
 module.exports = {
 0xCB98:0x222F,0xCB87:0x2230,0xC2B8:0x2231,0xCB99:0x2232,0xCB9D:0x2233,
@@ -1217,8 +1222,5 @@ module.exports = {
 0xE9BDB1:0x6D53,0xE9BDB3:0x6D54,0xE9BDB5:0x6D55,0xE9BDBA:0x6D56,0xE9BDBD:0x6D57,
 0xE9BE8F:0x6D58,0xE9BE90:0x6D59,0xE9BE91:0x6D5A,0xE9BE92:0x6D5B,0xE9BE94:0x6D5C,
 0xE9BE96:0x6D5D,0xE9BE97:0x6D5E,0xE9BE9E:0x6D5F,0xE9BEA1:0x6D60,0xE9BEA2:0x6D61,
-0xE9BEA3:0x6D62,0xE9BEA5:0x6D63,
-
-//FIXME: mojibake
-0xE3809C:0x2141
+0xE9BEA3:0x6D62,0xE9BEA5:0x6D63
 };
diff --git a/tests/test.js b/tests/test.js
index 34813c8..f55e487 100644
--- a/tests/test.js
+++ b/tests/test.js
@@ -1200,6 +1200,66 @@ describe('encoding', function() {
         });
       });
     });
+    it('Unicode aliases to SJIS', function() {
+      var aliasMaps = [
+        { input: [0x301C], sjis: [0x81, 0x60], decoded: [0xFF5E] }, // 〜 -> ～
+        { input: [0xFF5E], sjis: [0x81, 0x60], decoded: [0xFF5E] }, // ～ -> ～
+        { input: [0x00A2], sjis: [0x81, 0x91], decoded: [0xFFE0] }, // ¢ -> ￠
+        { input: [0xFFE0], sjis: [0x81, 0x91], decoded: [0xFFE0] }, // ￠ -> ￠
+        { input: [0x00A3], sjis: [0x81, 0x92], decoded: [0xFFE1] }, // £ -> ￡
+        { input: [0xFFE1], sjis: [0x81, 0x92], decoded: [0xFFE1] }, // ￡ -> ￡
+        { input: [0x2212], sjis: [0x81, 0x7C], decoded: [0xFF0D] }, // − -> －
+        { input: [0xFF0D], sjis: [0x81, 0x7C], decoded: [0xFF0D] }  // － -> －
+      ];
+
+      aliasMaps.forEach(function(alias) {
+        var sjis = encoding.convert(alias.input, { to: 'sjis', from: 'unicode' });
+        assert.deepEqual(sjis, alias.sjis);
+
+        var decodedUnicode = encoding.convert(sjis, { to: 'unicode', from: 'sjis' });
+        assert.deepEqual(decodedUnicode, alias.decoded);
+      });
+    });
+
+    it('Unicode aliases to EUC-JP and JIS', function() {
+      var aliasMaps = [
+        { input: [0x301C], eucjp: [0xA1, 0xC1], jis: [0x21, 0x41], decoded: [0xFF5E] }, // 〜 -> ～
+        { input: [0x00A2], eucjp: [0xA1, 0xF1], jis: [0x21, 0x71], decoded: [0xFFE0] }, // ¢ -> ￠
+        { input: [0x00A3], eucjp: [0xA1, 0xF2], jis: [0x21, 0x72], decoded: [0xFFE1] }, // £ -> ￡
+        { input: [0x2212], eucjp: [0xA1, 0xDD], jis: [0x21, 0x5D], decoded: [0xFF0D] }  // − -> －
+      ];
+
+      aliasMaps.forEach(function(alias) {
+        var eucjp = encoding.convert(alias.input, { to: 'euc-jp', from: 'unicode' });
+        assert.deepEqual(eucjp, alias.eucjp);
+
+        var decodedUnicode = encoding.convert(eucjp, { to: 'unicode', from: 'euc-jp' });
+        assert.deepEqual(decodedUnicode, alias.decoded);
+
+        var jis = encoding.convert(alias.input, { to: 'jis', from: 'unicode' });
+        assert.deepEqual(jis, [0x1B, 0x24, 0x42].concat(alias.jis, [0x1B, 0x28, 0x42]));
+      });
+    });
+
+    it('JIS X 0212 undefined code point', function() {
+      var undefinedCodePoint = [0x8F, 0xA1, 0xC1];
+      var decoded = encoding.convert(undefinedCodePoint, {
+        to: 'unicode', from: 'euc-jp', type: 'string'
+      });
+      assert.equal(decoded, '?');
+    });
+
+    it('SJIS invalid trail byte 0x7F', function() {
+      var invalidSjisCode = [0x81, 0x7F];
+      var validSjisCode = [0x81, 0x7E];
+
+      assert.equal(encoding.convert(invalidSjisCode, {
+        to: 'unicode', from: 'sjis', type: 'string'
+      }), '?');
+
+      var unicode = encoding.convert(validSjisCode, { to: 'unicode', from: 'sjis' });
+      assert.deepEqual(unicode, [0xD7]);
+    });
   });
 
   describe('urlEncode/urlDecode', function() {