diff --git a/ext/zstdruby/streaming_compress.c b/ext/zstdruby/streaming_compress.c
index 82f7047..4b1f165 100644
--- a/ext/zstdruby/streaming_compress.c
+++ b/ext/zstdruby/streaming_compress.c
@@ -125,6 +125,7 @@ rb_streaming_compress_compress(VALUE obj, VALUE src)
 
   struct streaming_compress_t* sc;
   TypedData_Get_Struct(obj, struct streaming_compress_t, &streaming_compress_type, sc);
+
   const char* output_data = RSTRING_PTR(sc->buf);
   VALUE result = rb_str_new(0, 0);
   while (input.pos < input.size) {
@@ -139,27 +140,54 @@ rb_streaming_compress_compress(VALUE obj, VALUE src)
 }
 
 static VALUE
-rb_streaming_compress_addstr(VALUE obj, VALUE src)
+rb_streaming_compress_write(int argc, VALUE *argv, VALUE obj)
 {
-  StringValue(src);
-  const char* input_data = RSTRING_PTR(src);
-  size_t input_size = RSTRING_LEN(src);
-  ZSTD_inBuffer input = { input_data, input_size, 0 };
-
+  size_t total = 0;
+  VALUE result = rb_str_new(0, 0);
   struct streaming_compress_t* sc;
   TypedData_Get_Struct(obj, struct streaming_compress_t, &streaming_compress_type, sc);
   const char* output_data = RSTRING_PTR(sc->buf);
-
-  while (input.pos < input.size) {
-    ZSTD_outBuffer output = { (void*)output_data, sc->buf_size, 0 };
-    size_t const result = ZSTD_compressStream2(sc->ctx, &output, &input, ZSTD_e_continue);
-    if (ZSTD_isError(result)) {
-      rb_raise(rb_eRuntimeError, "compress error error code: %s", ZSTD_getErrorName(result));
+  ZSTD_outBuffer output = { (void*)output_data, sc->buf_size, 0 };
+
+  while (argc-- > 0) {
+    VALUE str = *argv++;
+    StringValue(str);
+    const char* input_data = RSTRING_PTR(str);
+    size_t input_size = RSTRING_LEN(str);
+    ZSTD_inBuffer input = { input_data, input_size, 0 };
+
+    while (input.pos < input.size) {
+      size_t const ret = ZSTD_compressStream2(sc->ctx, &output, &input, ZSTD_e_continue);
+      if (ZSTD_isError(ret)) {
+        rb_raise(rb_eRuntimeError, "compress error error code: %s", ZSTD_getErrorName(ret));
+      }
+      total += RSTRING_LEN(str);
     }
   }
-  return obj;
+  return SIZET2NUM(total);
 }
 
+/*
+ * Document-method: <<
+ * Same as IO.
+ */
+#define rb_streaming_compress_addstr  rb_io_addstr
+/*
+ * Document-method: printf
+ * Same as IO.
+ */
+#define rb_streaming_compress_printf  rb_io_printf
+/*
+ * Document-method: print
+ * Same as IO.
+ */
+#define rb_streaming_compress_print  rb_io_print
+/*
+ * Document-method: puts
+ * Same as IO.
+ */
+#define rb_streaming_compress_puts  rb_io_puts
+
 static VALUE
 rb_streaming_compress_flush(VALUE obj)
 {
@@ -186,7 +214,12 @@ zstd_ruby_streaming_compress_init(void)
   rb_define_alloc_func(cStreamingCompress, rb_streaming_compress_allocate);
   rb_define_method(cStreamingCompress, "initialize", rb_streaming_compress_initialize, -1);
   rb_define_method(cStreamingCompress, "compress", rb_streaming_compress_compress, 1);
+  rb_define_method(cStreamingCompress, "write", rb_streaming_compress_write, -1);
   rb_define_method(cStreamingCompress, "<<", rb_streaming_compress_addstr, 1);
+  rb_define_method(cStreamingCompress, "printf", rb_streaming_compress_printf, -1);
+  rb_define_method(cStreamingCompress, "print", rb_streaming_compress_print, -1);
+  rb_define_method(cStreamingCompress, "puts", rb_streaming_compress_puts, -1);
+
   rb_define_method(cStreamingCompress, "flush", rb_streaming_compress_flush, 0);
   rb_define_method(cStreamingCompress, "finish", rb_streaming_compress_finish, 0);
 
@@ -194,4 +227,3 @@ zstd_ruby_streaming_compress_init(void)
   rb_define_const(cStreamingCompress, "FLUSH", INT2FIX(ZSTD_e_flush));
   rb_define_const(cStreamingCompress, "END", INT2FIX(ZSTD_e_end));
 }
-
diff --git a/ext/zstdruby/streaming_decompress.c b/ext/zstdruby/streaming_decompress.c
index 6796596..c580f0a 100644
--- a/ext/zstdruby/streaming_decompress.c
+++ b/ext/zstdruby/streaming_decompress.c
@@ -101,35 +101,13 @@ rb_streaming_decompress_decompress(VALUE obj, VALUE src)
     ZSTD_outBuffer output = { (void*)output_data, sd->buf_size, 0 };
     size_t const ret = ZSTD_decompressStream(sd->ctx, &output, &input);
     if (ZSTD_isError(ret)) {
-      rb_raise(rb_eRuntimeError, "compress error error code: %s", ZSTD_getErrorName(ret));
+      rb_raise(rb_eRuntimeError, "decompress error error code: %s", ZSTD_getErrorName(ret));
     }
     rb_str_cat(result, output.dst, output.pos);
   }
   return result;
 }
 
-static VALUE
-rb_streaming_decompress_addstr(VALUE obj, VALUE src)
-{
-  StringValue(src);
-  const char* input_data = RSTRING_PTR(src);
-  size_t input_size = RSTRING_LEN(src);
-  ZSTD_inBuffer input = { input_data, input_size, 0 };
-
-  struct streaming_decompress_t* sd;
-  TypedData_Get_Struct(obj, struct streaming_decompress_t, &streaming_decompress_type, sd);
-  const char* output_data = RSTRING_PTR(sd->buf);
-
-  while (input.pos < input.size) {
-    ZSTD_outBuffer output = { (void*)output_data, sd->buf_size, 0 };
-    size_t const result = ZSTD_decompressStream(sd->ctx, &output, &input);
-    if (ZSTD_isError(result)) {
-      rb_raise(rb_eRuntimeError, "compress error error code: %s", ZSTD_getErrorName(result));
-    }
-  }
-  return obj;
-}
-
 extern VALUE rb_mZstd, cStreamingDecompress;
 void
 zstd_ruby_streaming_decompress_init(void)
@@ -138,6 +116,4 @@ zstd_ruby_streaming_decompress_init(void)
   rb_define_alloc_func(cStreamingDecompress, rb_streaming_decompress_allocate);
   rb_define_method(cStreamingDecompress, "initialize", rb_streaming_decompress_initialize, 0);
   rb_define_method(cStreamingDecompress, "decompress", rb_streaming_decompress_decompress, 1);
-  rb_define_method(cStreamingDecompress, "<<", rb_streaming_decompress_addstr, 1);
 }
-
diff --git a/lib/zstd-ruby/stream_reader.rb b/lib/zstd-ruby/stream_reader.rb
new file mode 100644
index 0000000..0efef9c
--- /dev/null
+++ b/lib/zstd-ruby/stream_reader.rb
@@ -0,0 +1,22 @@
+module Zstd
+  # @todo Exprimental
+  class StreamReader
+    def initialize(io)
+      @io = io
+      @stream = Zstd::StreamingDecompress.new
+    end
+
+    def read(length)
+      if @io.eof?
+        raise StandardError, "EOF"
+      end
+      data = @io.read(length)
+      @stream.decompress(data)
+    end
+
+    def close
+      @io.write(@stream.finish)
+      @io.close
+    end
+  end
+end
diff --git a/lib/zstd-ruby/stream_writer.rb b/lib/zstd-ruby/stream_writer.rb
new file mode 100644
index 0000000..3e379bf
--- /dev/null
+++ b/lib/zstd-ruby/stream_writer.rb
@@ -0,0 +1,23 @@
+module Zstd
+  # @todo Exprimental
+  class StreamWriter
+    def initialize(io, level: nil)
+      @io = io
+      @stream = Zstd::StreamingCompress.new(level)
+    end
+
+    def write(*data)
+      @stream.write(*data)
+      @io.write(@stream.flush)
+    end
+
+    def finish
+      @io.write(@stream.finish)
+    end
+
+    def close
+      @io.write(@stream.finish)
+      @io.close
+    end
+  end
+end
diff --git a/spec/zstd-ruby-stream_reader_spec.rb b/spec/zstd-ruby-stream_reader_spec.rb
new file mode 100644
index 0000000..9b0f049
--- /dev/null
+++ b/spec/zstd-ruby-stream_reader_spec.rb
@@ -0,0 +1,23 @@
+require "spec_helper"
+require 'zstd-ruby'
+require 'zstd-ruby/stream_writer'
+require 'zstd-ruby/stream_reader'
+require 'pry'
+
+RSpec.describe Zstd::StreamReader do
+  describe 'read' do
+    it 'shoud work' do
+      io = StringIO.new
+      writer = Zstd::StreamWriter.new(io)
+      writer.write("abc")
+      writer.write("def")
+      writer.finish
+      io.rewind
+
+      reader = Zstd::StreamReader.new(io)
+      expect(reader.read(10)).to eq('a')
+      expect(reader.read(10)).to eq('bcdef')
+      expect(reader.read(10)).to eq('')
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/zstd-ruby-stream_writer_spec.rb b/spec/zstd-ruby-stream_writer_spec.rb
new file mode 100644
index 0000000..268e099
--- /dev/null
+++ b/spec/zstd-ruby-stream_writer_spec.rb
@@ -0,0 +1,17 @@
+require "spec_helper"
+require 'zstd-ruby'
+require 'zstd-ruby/stream_writer'
+
+RSpec.describe Zstd::StreamWriter do
+  describe 'write' do
+    it 'shoud work' do
+      io = StringIO.new
+      stream = Zstd::StreamWriter.new(io)
+      stream.write("abc")
+      stream.write("def")
+      stream.finish
+      io.rewind
+      expect(Zstd.decompress(io.read)).to eq('abcdef')
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/zstd-ruby-streaming-compress_spec.rb b/spec/zstd-ruby-streaming-compress_spec.rb
index 5c3f3b4..84ac8dd 100644
--- a/spec/zstd-ruby-streaming-compress_spec.rb
+++ b/spec/zstd-ruby-streaming-compress_spec.rb
@@ -66,4 +66,3 @@
     end
   end
 end
-
diff --git a/spec/zstd-ruby_spec.rb b/spec/zstd-ruby_spec.rb
index 35a8c28..36ed267 100644
--- a/spec/zstd-ruby_spec.rb
+++ b/spec/zstd-ruby_spec.rb
@@ -60,6 +60,13 @@ def to_str
       expect(decompressed).to eq('')
     end
 
+    it 'should work for non-ascii string' do
+      compressed = Zstd.compress('あああ')
+      expect(compressed.bytesize).to eq(18)
+      decompressed = Zstd.decompress(compressed)
+      expect(decompressed.force_encoding('UTF-8')).to eq('あああ')
+    end
+
     it 'should raise exception with unsupported object' do
       expect { Zstd.decompress(Object.new) }.to raise_error(TypeError)
     end
diff --git a/zstd-ruby.gemspec b/zstd-ruby.gemspec
index 5b5a0de..a0d0b68 100644
--- a/zstd-ruby.gemspec
+++ b/zstd-ruby.gemspec
@@ -35,4 +35,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rake-compiler", '~> 1'
   spec.add_development_dependency "rspec", "~> 3.0"
+  spec.add_development_dependency "pry"
 end