diff --git a/src/yycc/encoding/iconv.cpp b/src/yycc/encoding/iconv.cpp
index 66407ec..c102934 100644
--- a/src/yycc/encoding/iconv.cpp
+++ b/src/yycc/encoding/iconv.cpp
@@ -75,8 +75,22 @@ namespace yycc::encoding::iconv {
                 that_iconv_close(this->inner);
             }
         }
+        PrivToken(PrivToken&& rhs) : inner(rhs.inner) {
+            // Reset rhs inner
+            rhs.inner = INVALID_ICONV_TOKEN;
+        }
+        PrivToken& operator=(PrivToken&& rhs) {
+            // Free self first
+            if (this->inner != INVALID_ICONV_TOKEN) {
+                that_iconv_close(this->inner);
+            }
+            // Copy rhs inner and reset it.
+            this->inner = rhs.inner;
+            rhs.inner = INVALID_ICONV_TOKEN;
+            // Return self
+            return *this;
+        }
         YYCC_DELETE_COPY(PrivToken)
-        YYCC_DEFAULT_MOVE(PrivToken)
 
         bool is_valid() const { return this->inner != INVALID_ICONV_TOKEN; }
         that_iconv_t get_inner() const { return this->inner; }
diff --git a/src/yycc/encoding/iconv.hpp b/src/yycc/encoding/iconv.hpp
index 5d62d5c..b1a5790 100644
--- a/src/yycc/encoding/iconv.hpp
+++ b/src/yycc/encoding/iconv.hpp
@@ -40,9 +40,9 @@ namespace yycc::encoding::iconv {
 
     /// @private
     enum class ConvError {
-        InvalidCd, ///< Given token is invalid.
-        NullPointer, ///< Some of essential pointer in argument is nullptr.
-        InvalidMbSeq, ///< An invalid multibyte sequence has been encountered in the input.
+        InvalidCd,       ///< Given token is invalid.
+        NullPointer,     ///< Some of essential pointer in argument is nullptr.
+        InvalidMbSeq,    ///< An invalid multibyte sequence has been encountered in the input.
         IncompleteMbSeq, ///< An incomplete multibyte sequence has been encountered in the input.
     };
 
@@ -50,6 +50,145 @@ namespace yycc::encoding::iconv {
     template<typename T>
     using ConvResult = NS_YYCC_PATCH_EXPECTED::Expected<T, ConvError>;
 
+    // TODO: 为下列类添加注释时，指明static开头的是一次性使用的，适用于转换一两次结束。
+    // 用实例类的适用于需要持续转换的。
+
+    // Char -> UTF8
+    class CharToUtf8 {
+    public:
+        CharToUtf8(const CodeName& code_name);
+        ~CharToUtf8();
+        YYCC_DELETE_COPY(CharToUtf8)
+        YYCC_DEFAULT_MOVE(CharToUtf8)
+
+    public:
+        ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::string_view& src);
+        bool to_utf8(const std::string_view& src, NS_YYCC_STRING::u8string& dst);
+        NS_YYCC_STRING::u8string to_utf8(const std::string_view& src);
+
+    private:
+        Token token;
+    };
+
+    // UTF8 -> Char
+    class Utf8ToChar {
+    public:
+        Utf8ToChar(const CodeName& code_name);
+        ~Utf8ToChar();
+        YYCC_DELETE_COPY(Utf8ToChar)
+        YYCC_DEFAULT_MOVE(Utf8ToChar)
+
+    public:
+        ConvResult<std::string> priv_to_char(const NS_YYCC_STRING::u8string_view& src);
+        bool to_char(const NS_YYCC_STRING::u8string_view& src, std::string& dst);
+        std::string to_char(const NS_YYCC_STRING::u8string_view& src);
+
+    private:
+        Token token;
+    };
+
+    // WChar -> Char
+    class WcharToChar {
+    public:
+        WcharToChar(const CodeName& code_name);
+        ~WcharToChar();
+        YYCC_DELETE_COPY(WcharToChar)
+        YYCC_DEFAULT_MOVE(WcharToChar)
+
+    public:
+        ConvResult<std::string> priv_to_char(const std::wstring_view& src);
+        bool to_char(const std::wstring_view& src, std::string& dst);
+        std::string to_char(const std::wstring_view& src);
+
+    private:
+        Token token;
+    };
+
+    // Char -> WChar
+    class CharToWchar {
+    public:
+        CharToWchar(const CodeName& code_name);
+        ~CharToWchar();
+        YYCC_DELETE_COPY(CharToWchar)
+        YYCC_DEFAULT_MOVE(CharToWchar)
+
+    public:
+        ConvResult<std::wstring> priv_to_wchar(const std::string_view& src, const CodeName& code_name);
+        bool to_wchar(const std::string_view& src, std::wstring& dst, const CodeName& code_name);
+        std::wstring to_wchar(const std::string_view& src, const CodeName& code_name);
+
+    private:
+        Token token;
+    };
+
+    // UTF8 -> UTF16
+    class Utf8ToUtf16 {
+    public:
+        Utf8ToUtf16();
+        ~Utf8ToUtf16();
+        YYCC_DELETE_COPY(Utf8ToUtf16)
+        YYCC_DEFAULT_MOVE(Utf8ToUtf16)
+
+    public:
+        ConvResult<std::u16string> priv_to_utf16(const NS_YYCC_STRING::u8string_view& src);
+        bool to_utf16(const NS_YYCC_STRING::u8string_view& src, std::u16string& dst);
+        std::u16string to_utf16(const NS_YYCC_STRING::u8string_view& src);
+
+    private:
+        Token token;
+    };
+
+    // UTF16 -> UTF8
+    class Utf16ToUtf8 {
+    public:
+        Utf16ToUtf8();
+        ~Utf16ToUtf8();
+        YYCC_DELETE_COPY(Utf16ToUtf8)
+        YYCC_DEFAULT_MOVE(Utf16ToUtf8)
+
+    public:
+        ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u16string_view& src);
+        bool to_utf8(const std::u16string_view& src, NS_YYCC_STRING::u8string& dst);
+        NS_YYCC_STRING::u8string to_utf8(const std::u16string_view& src);
+
+    private:
+        Token token;
+    };
+
+    // UTF8 -> UTF32
+    class Utf8ToUtf32 {
+    public:
+        Utf8ToUtf32();
+        ~Utf8ToUtf32();
+        YYCC_DELETE_COPY(Utf8ToUtf32)
+        YYCC_DEFAULT_MOVE(Utf8ToUtf32)
+
+    public:
+        ConvResult<std::u32string> priv_to_utf32(const NS_YYCC_STRING::u8string_view& src);
+        bool to_utf32(const NS_YYCC_STRING::u8string_view& src, std::u32string& dst);
+        std::u32string to_utf32(const NS_YYCC_STRING::u8string_view& src);
+
+    private:
+        Token token;
+    };
+
+    // UTF32 -> UTF8
+    class Utf32ToUtf8 {
+    public:
+        Utf32ToUtf8();
+        ~Utf32ToUtf8();
+        YYCC_DELETE_COPY(Utf32ToUtf8)
+        YYCC_DEFAULT_MOVE(Utf32ToUtf8)
+
+    public:
+        ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u32string_view& src);
+        bool to_utf8(const std::u32string_view& src, NS_YYCC_STRING::u8string& dst);
+        NS_YYCC_STRING::u8string to_utf8(const std::u32string_view& src);
+
+    private:
+        Token token;
+    };
+
 } // namespace yycc::encoding::iconv
 
 #undef NS_YYCC_PATCH_EXPECTED
diff --git a/src/yycc/encoding/utf.hpp b/src/yycc/encoding/utf.hpp
index ea9b2a6..8cac4cc 100644
--- a/src/yycc/encoding/utf.hpp
+++ b/src/yycc/encoding/utf.hpp
@@ -15,25 +15,21 @@ namespace yycc::encoding::utf {
     using ConvResult = NS_YYCC_PATCH_EXPECTED::Expected<T, ConvError>;
 
     // UTF8 -> UTF16
-
     ConvResult<std::u16string> priv_to_utf16(const NS_YYCC_STRING::u8string_view& src);
     bool to_utf16(const NS_YYCC_STRING::u8string_view& src, std::u16string& dst);
     std::u16string to_utf16(const NS_YYCC_STRING::u8string_view& src);
 
     // UTF16 -> UTF8
-
     ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u16string_view& src);
     bool to_utf8(const std::u16string_view& src, NS_YYCC_STRING::u8string& dst);
     NS_YYCC_STRING::u8string to_utf8(const std::u16string_view& src);
 
     // UTF8 -> UTF32
-
     ConvResult<std::u32string> priv_to_utf32(const NS_YYCC_STRING::u8string_view& src);
     bool to_utf32(const NS_YYCC_STRING::u8string_view& src, std::u32string& dst);
     std::u32string to_utf32(const NS_YYCC_STRING::u8string_view& src);
 
     // UTF32 -> UTF8
-
     ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u32string_view& src);
     bool to_utf8(const std::u32string_view& src, NS_YYCC_STRING::u8string& dst);
     NS_YYCC_STRING::u8string to_utf8(const std::u32string_view& src);
diff --git a/src/yycc/encoding/windows.cpp b/src/yycc/encoding/windows.cpp
index ccf9606..aaa62d4 100644
--- a/src/yycc/encoding/windows.cpp
+++ b/src/yycc/encoding/windows.cpp
@@ -241,9 +241,13 @@ namespace yycc::encoding::windows {
 
 #pragma endregion
 
+    // YYC MARK:
+    // The convertion between UTF is implemented by c16rtomb, c32rtomb, mbrtoc16 and mbrtoc32.
+    // These function is locale related in C++ standard, but in Microsoft STL, it's only for UTF8.
+    // So we can use them safely in Win32 environment.
+
 #undef CONVFN_TYPE1
 #undef CONVFN_TYPE2
-#undef CONVFCT_TYPE4
 
 } // namespace yycc::encoding::windows
 
diff --git a/src/yycc/encoding/windows.hpp b/src/yycc/encoding/windows.hpp
index acba7d4..dfec5d8 100644
--- a/src/yycc/encoding/windows.hpp
+++ b/src/yycc/encoding/windows.hpp
@@ -65,6 +65,26 @@ namespace yycc::encoding::windows {
     bool to_char(const NS_YYCC_STRING::u8string_view& src, std::string& dst, CodePage code_page);
     std::string to_char(const NS_YYCC_STRING::u8string_view& src, CodePage code_page);
 
+    // UTF8 -> UTF16
+    ConvResult<std::u16string> priv_to_utf16(const NS_YYCC_STRING::u8string_view& src);
+    bool to_utf16(const NS_YYCC_STRING::u8string_view& src, std::u16string& dst);
+    std::u16string to_utf16(const NS_YYCC_STRING::u8string_view& src);
+
+    // UTF16 -> UTF8
+    ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u16string_view& src);
+    bool to_utf8(const std::u16string_view& src, NS_YYCC_STRING::u8string& dst);
+    NS_YYCC_STRING::u8string to_utf8(const std::u16string_view& src);
+
+    // UTF8 -> UTF32
+    ConvResult<std::u32string> priv_to_utf32(const NS_YYCC_STRING::u8string_view& src);
+    bool to_utf32(const NS_YYCC_STRING::u8string_view& src, std::u32string& dst);
+    std::u32string to_utf32(const NS_YYCC_STRING::u8string_view& src);
+
+    // UTF32 -> UTF8
+    ConvResult<NS_YYCC_STRING::u8string> priv_to_utf8(const std::u32string_view& src);
+    bool to_utf8(const std::u32string_view& src, NS_YYCC_STRING::u8string& dst);
+    NS_YYCC_STRING::u8string to_utf8(const std::u32string_view& src);
+
 } // namespace yycc::encoding::windows
 
 #undef NS_YYCC_PATCH_EXPECTED