diff --git a/.rubocop.yml b/.rubocop.yml
index e62aa6e..61625b1 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -28,6 +28,14 @@ Style/SingleLineMethods:
 Style/StderrPuts:
   Enabled: false
 
+Style/GlobalVars:
+  Exclude:
+    - mrblib/rf/container.rb
+
+Style/SpecialGlobalVars:
+  Exclude:
+    - mrblib/rf/container.rb
+
 Security/YAMLLoad:
   Enabled: false
 
@@ -43,6 +51,14 @@ Naming/MemoizedInstanceVariableName:
   Exclude:
     - mrblib/rf/container.rb
 
+Naming/MethodName:
+  Exclude:
+    - mrblib/rf/container.rb
+
+Naming/VariableName:
+  Exclude:
+    - mrblib/rf/container.rb
+
 RSpec/ContextWording:
   Prefixes:
     - when
diff --git a/README.md b/README.md
index b067063..d4a66b2 100644
--- a/README.md
+++ b/README.md
@@ -177,13 +177,10 @@ In rf, you can use [special variables](https://docs.ruby-lang.org/ja/latest/clas
 
 | Variable name | Description |
 |-------|------|
-| \_  | The input record |
-| $\_ | Same as \_ |
-| $F | It is an array that stores fields(`$F=_.split`) |
-| \_0 | Same as \_ |
+| record, \_, $\_, \_0  | The input record |
+| fields, $F | It is an array that stores fields(`$F=_.split`) |
 | \_1, \_2, \_3, ... | First field, second field, third field... |
-| $. | The number of records loaded(1-indexed) |
-| @NR | Same as $. |
+| $., @NR | The number of records loaded(1-indexed) |
 
 ## Built-in methods
 
diff --git a/README_ja.md b/README_ja.md
index 7f3cf22..dbc9f9d 100644
--- a/README_ja.md
+++ b/README_ja.md
@@ -184,13 +184,10 @@ rfではRubyで定義されている[特殊変数](https://docs.ruby-lang.org/ja
 
 | 変数名 | 説明 |
 |-------|------|
-| \_  | 入力されたレコードです |
-| $\_ | \_ のエイリアスです |
-| $F | フィールドを格納した配列です(`$F=_.split`) |
-| \_0 | \_ と等価です |
+| record, \_, $\_, \_0  | 入力されたレコードです |
+| fields, $F | フィールドを格納した配列です(`fields=_.split`) |
 | \_1, \_2, \_3, ... | 1番目、2番目、3番目のフィールドです |
-| $. | 1始まりの読み込んだレコード数です |
-| @NR | $.と同じです |
+| $., @NR | 1始まりの読み込んだレコード数です |
 
 ## 組み込みメソッド
 
diff --git a/mrblib/rf/00filter/base.rb b/mrblib/rf/00filter/base.rb
index d33dade..e6e1dea 100644
--- a/mrblib/rf/00filter/base.rb
+++ b/mrblib/rf/00filter/base.rb
@@ -4,7 +4,7 @@ class Base
       attr_reader :data, :record, :index, :fields
 
       def each_record
-        index = 0
+        index = 1
         data.each do |record|
           @record = preprocess(record)
           @index = index
diff --git a/mrblib/rf/cli.rb b/mrblib/rf/cli.rb
index 81a0441..cfafd0c 100644
--- a/mrblib/rf/cli.rb
+++ b/mrblib/rf/cli.rb
@@ -30,14 +30,12 @@ def pre_action
 
     def do_action
       filter.each_record do |record, index, fields|
-        container._ = record
-        container.NR = $. = index + 1
-        $F = fields # rubocop:disable Style/GlobalVars
+        container.record = record
+        container.NR = index
+        container.fields = fields
 
         ret = bind.eval(command)
-        next if config.quiet
-
-        filter.output(ret)
+        filter.output(ret) unless config.quiet
       end
     end
 
diff --git a/mrblib/rf/container.rb b/mrblib/rf/container.rb
index bcb09db..40f6e6b 100644
--- a/mrblib/rf/container.rb
+++ b/mrblib/rf/container.rb
@@ -1,14 +1,31 @@
 module Rf
   class Container
     def _
-      $_ # rubocop:disable Style/SpecialGlobalVars
+      $_
     end
 
     def _=(data)
       $_ = data
     end
 
-    attr_accessor :NR # rubocop:disable Naming/MethodName
+    alias record _
+    alias record= _=
+
+    def fields
+      $F
+    end
+
+    def fields=(data)
+      $F = data
+    end
+
+    def NR
+      @NR ||= 1
+    end
+
+    def NR=(num)
+      @NR = $. = num
+    end
 
     def string?
       _.instance_of?(String)
@@ -41,7 +58,7 @@ def method_missing(sym, *)
       if sym == :_0
         _
       elsif s =~ /\A_[1-9]\d*\z/
-        $F[s[1..].to_i - 1] # rubocop:disable Style/GlobalVars
+        $F[s[1..].to_i - 1]
       else
         super
       end
diff --git a/spec/special_variables_spec.rb b/spec/special_variables_spec.rb
index 9b798bb..ea9502b 100644
--- a/spec/special_variables_spec.rb
+++ b/spec/special_variables_spec.rb
@@ -1,133 +1,109 @@
 describe 'Special Variables' do
-  describe '$_' do
-    let(:input) { 'foo' }
-    let(:output) { input }
-
-    before { run_rf('-q "puts $_"', input) }
-
-    it { expect(last_command_started).to be_successfully_executed }
-    it { expect(last_command_started).to have_output output_string_eq output }
-  end
+  context 'for record variables' do
+    where(:name) do
+      %w[record $_ _ _0]
+    end
 
-  describe '_' do
-    let(:input) { 'foo' }
-    let(:output) { input }
+    with_them do
+      let(:input) { 'foo' }
+      let(:output) { input }
 
-    before { run_rf('-q "puts _"', input) }
+      before { run_rf("-q 'puts #{name}'", input) }
 
-    it { expect(last_command_started).to be_successfully_executed }
-    it { expect(last_command_started).to have_output output_string_eq output }
+      it { expect(last_command_started).to be_successfully_executed }
+      it { expect(last_command_started).to have_output output_string_eq output }
+    end
   end
 
-  describe '_0' do
-    let(:input) { 'foo' }
-    let(:output) { input }
-
-    before { run_rf('-q "puts _0"', input) }
+  context 'for fields variables' do
+    where(:name) do
+      %w[fields $F]
+    end
 
-    it { expect(last_command_started).to be_successfully_executed }
-    it { expect(last_command_started).to have_output output_string_eq output }
-  end
+    with_them do
+      context 'when record is String' do
+        let(:input) { 'foo bar baz' }
+        let(:output) do
+          <<~OUTPUT
+            "foo"
+            "bar"
+            "baz"
+          OUTPUT
+        end
+
+        before { run_rf('-q "p $F[0],$F[1],$F[2]"', input) }
+
+        it { expect(last_command_started).to be_successfully_executed }
+        it { expect(last_command_started).to have_output output_string_eq output }
+      end
 
-  describe '$F' do
-    context 'when record is String' do
-      let(:input) { 'foo bar baz' }
-      let(:output) do
-        <<~OUTPUT
-          "foo"
-          "bar"
-          "baz"
-        OUTPUT
+      context 'when record is Hash' do
+        let(:input) do
+          <<~JSON
+            {
+              "a": 1,
+              "b": 2,
+              "c": 3
+            }
+          JSON
+        end
+        let(:output) do
+          <<~OUTPUT
+            ["a", 1]
+            ["b", 2]
+            ["c", 3]
+          OUTPUT
+        end
+
+        before { run_rf("-j -q 'p #{name}[0],#{name}[1],#{name}[2]'", input) }
+
+        it { expect(last_command_started).to be_successfully_executed }
+        it { expect(last_command_started).to have_output output_string_eq output }
       end
 
-      before { run_rf('-q "p $F[0],$F[1],$F[2]"', input) }
+      context 'when record is Other class' do
+        let(:input) { '1' }
+        let(:output) do
+          <<~OUTPUT
+            1
+            nil
+            nil
+          OUTPUT
+        end
 
-      it { expect(last_command_started).to be_successfully_executed }
-      it { expect(last_command_started).to have_output output_string_eq output }
-    end
+        before { run_rf("-j -q 'p #{name}[0],#{name}[1],#{name}[2]'", input) }
 
-    context 'when record is Hash' do
-      let(:input) do
-        <<~JSON
-          {
-            "a": 1,
-            "b": 2,
-            "c": 3
-          }
-        JSON
+        it { expect(last_command_started).to be_successfully_executed }
+        it { expect(last_command_started).to have_output output_string_eq output }
       end
-      let(:output) do
-        <<~OUTPUT
-          ["a", 1]
-          ["b", 2]
-          ["c", 3]
-        OUTPUT
-      end
-
-      before { run_rf('-j -q "p $F[0],$F[1],$F[2]"', input) }
+    end
+  end
 
-      it { expect(last_command_started).to be_successfully_executed }
-      it { expect(last_command_started).to have_output output_string_eq output }
+  context 'for number of records' do
+    where(:name) do
+      %w[$. NR]
     end
 
-    context 'when record is Other class' do
-      let(:input) { '1' }
+    with_them do
+      let(:input) do
+        <<~TEXT
+          foo
+          bar
+          baz
+        TEXT
+      end
       let(:output) do
         <<~OUTPUT
-          1
-          nil
-          nil
+          1 foo
+          2 bar
+          3 baz
         OUTPUT
       end
 
-      before { run_rf('-j -q "p $F[0],$F[1],$F[2]"', input) }
+      before { run_rf(%q/'[$.,_].join(" ")'/, input) }
 
       it { expect(last_command_started).to be_successfully_executed }
       it { expect(last_command_started).to have_output output_string_eq output }
     end
   end
-
-  describe '$.' do
-    let(:input) do
-      <<~TEXT
-        foo
-        bar
-        baz
-      TEXT
-    end
-    let(:output) do
-      <<~OUTPUT
-        1 foo
-        2 bar
-        3 baz
-      OUTPUT
-    end
-
-    before { run_rf(%q/'[$.,_].join(" ")'/, input) }
-
-    it { expect(last_command_started).to be_successfully_executed }
-    it { expect(last_command_started).to have_output output_string_eq output }
-  end
-
-  describe '@NR' do
-    let(:input) do
-      <<~TEXT
-        foo
-        bar
-        baz
-      TEXT
-    end
-    let(:output) do
-      <<~OUTPUT
-        1 foo
-        2 bar
-        3 baz
-      OUTPUT
-    end
-
-    before { run_rf(%q/'[@NR,_].join(" ")'/, input) }
-
-    it { expect(last_command_started).to be_successfully_executed }
-    it { expect(last_command_started).to have_output output_string_eq output }
-  end
 end