diff --git a/VimR.xcodeproj/project.pbxproj b/VimR.xcodeproj/project.pbxproj
index 75f06d19..229ad8ac 100644
--- a/VimR.xcodeproj/project.pbxproj
+++ b/VimR.xcodeproj/project.pbxproj
@@ -28,6 +28,7 @@
 		4B401B161D0454E900D99EDC /* PureLayout.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = 4B401B131D0454DC00D99EDC /* PureLayout.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		4B401B1A1D046E0600D99EDC /* NeoVimViewDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B401B191D046E0600D99EDC /* NeoVimViewDelegate.swift */; };
 		4B4192181D0C52D700A0BEB2 /* Grid.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B4192171D0C52D700A0BEB2 /* Grid.swift */; };
+		4B4546871D468CEC00A1E27F /* PrefStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B4546861D468CEC00A1E27F /* PrefStore.swift */; };
 		4B4FC8E61D3E8739009352C3 /* PrefWindowComponent.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B4FC8E51D3E8739009352C3 /* PrefWindowComponent.swift */; };
 		4B56F2931D29903F00C1F92E /* SwiftNeoVimTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 4B56F2921D29903F00C1F92E /* SwiftNeoVimTests.swift */; };
 		4B56F2951D29903F00C1F92E /* SwiftNeoVim.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 4B2A2BF71D0351810074CE9A /* SwiftNeoVim.framework */; };
@@ -168,6 +169,7 @@
 		4B401B131D0454DC00D99EDC /* PureLayout.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = PureLayout.framework; path = Carthage/Build/Mac/PureLayout.framework; sourceTree = SOURCE_ROOT; };
 		4B401B191D046E0600D99EDC /* NeoVimViewDelegate.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NeoVimViewDelegate.swift; sourceTree = "<group>"; };
 		4B4192171D0C52D700A0BEB2 /* Grid.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Grid.swift; sourceTree = "<group>"; };
+		4B4546861D468CEC00A1E27F /* PrefStore.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PrefStore.swift; sourceTree = "<group>"; };
 		4B4FC8E51D3E8739009352C3 /* PrefWindowComponent.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PrefWindowComponent.swift; sourceTree = "<group>"; };
 		4B56F2901D29903F00C1F92E /* SwiftNeoVimTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = SwiftNeoVimTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		4B56F2921D29903F00C1F92E /* SwiftNeoVimTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SwiftNeoVimTests.swift; sourceTree = "<group>"; };
@@ -270,6 +272,7 @@
 		4B238BED1D3ED55300CBDD98 /* Preferences */ = {
 			isa = PBXGroup;
 			children = (
+				4B4546861D468CEC00A1E27F /* PrefStore.swift */,
 				4B4FC8E51D3E8739009352C3 /* PrefWindowComponent.swift */,
 				4B238BEB1D3ED54D00CBDD98 /* AppearancePrefPane.swift */,
 			);
@@ -697,6 +700,7 @@
 				4BD3BF971D32B0DB00082605 /* MainWindowManager.swift in Sources */,
 				4B238BEC1D3ED54D00CBDD98 /* AppearancePrefPane.swift in Sources */,
 				4BD3BF931D32A95800082605 /* MainWindowComponent.swift in Sources */,
+				4B4546871D468CEC00A1E27F /* PrefStore.swift in Sources */,
 				4B4FC8E61D3E8739009352C3 /* PrefWindowComponent.swift in Sources */,
 				4BEBA5091CFF374B00673FDF /* AppDelegate.swift in Sources */,
 				1929B165820D7177743B537A /* Component.swift in Sources */,
diff --git a/VimR/AppDelegate.swift b/VimR/AppDelegate.swift
index 0e36b002..a3686eb7 100644
--- a/VimR/AppDelegate.swift
+++ b/VimR/AppDelegate.swift
@@ -10,10 +10,15 @@ import PureLayout
 @NSApplicationMain
 class AppDelegate: NSObject, NSApplicationDelegate {
 
-  @IBOutlet weak var window: NSWindow!
+  private let prefStore = PrefStore(source: Observable.empty())
 
-  private let prefWindowComponent = PrefWindowComponent(source: Observable.empty())
   private let mainWindowManager: MainWindowManager
+  private let prefWindowComponent = PrefWindowComponent(source: Observable.empty())
+
+  override init() {
+    self.mainWindowManager = MainWindowManager(prefWindowComponent: self.prefWindowComponent)
+    super.init()
+  }
 
   @IBAction func debugSomething(sender: AnyObject!) {
     NSLog("debug sth...")
@@ -27,11 +32,6 @@ class AppDelegate: NSObject, NSApplicationDelegate {
     self.prefWindowComponent.show()
   }
 
-  override init() {
-    self.mainWindowManager = MainWindowManager(prefWindowComponent: self.prefWindowComponent)
-    super.init()
-  }
-  
   func applicationDidFinishLaunching(aNotification: NSNotification) {
 //    let testView = InputTestView(frame: CGRect(x: 0, y: 0, width: 300, height: 300))
 //    self.window.contentView?.addSubview(testView)
diff --git a/VimR/Component.swift b/VimR/Component.swift
index 65fa2fac..566b102d 100644
--- a/VimR/Component.swift
+++ b/VimR/Component.swift
@@ -6,10 +6,14 @@
 import Foundation
 import RxSwift
 
-protocol Component {
+protocol Flow {
   var sink: Observable<Any> { get }
 }
 
+protocol Store: Flow {}
+
+protocol Component: Flow {}
+
 protocol ViewComponent: Component {
   var view: NSView { get }
 }
diff --git a/VimR/PrefStore.swift b/VimR/PrefStore.swift
new file mode 100644
index 00000000..01028e9b
--- /dev/null
+++ b/VimR/PrefStore.swift
@@ -0,0 +1,86 @@
+/**
+ * Tae Won Ha - http://taewon.de - @hataewon
+ * See LICENSE
+ */
+
+import Foundation
+import RxSwift
+
+private class PrefKeys {
+
+  static let editorFontName = "editor-font-name"
+  static let editorFontSize = "editor-font-size"
+}
+
+class PrefStore: Store {
+
+  private static let compatibleVersion = "38"
+  private static let defaultEditorFont = NSFont(name: "Menlo", size: 13)!
+  private static let minimumEditorFontSize = CGFloat(4)
+  private static let maximumEditorFontSize = CGFloat(128)
+
+  private let source: Observable<Any>
+  private let disposeBag = DisposeBag()
+
+  private let subject = PublishSubject<Any>()
+  var sink: Observable<Any> {
+    return self.subject.asObservable()
+  }
+
+  private let userDefaults = NSUserDefaults.standardUserDefaults()
+  private let fontManager = NSFontManager.sharedFontManager()
+
+  private var data = PrefData(appearance: AppearancePrefData(editorFont: PrefStore.defaultEditorFont))
+
+  init(source: Observable<Any>) {
+    self.source = source
+
+    if let prefs = self.userDefaults.dictionaryForKey(PrefStore.compatibleVersion) {
+      self.data = self.prefDataFromDict(prefs)
+    } else {
+      self.userDefaults.setValue(self.prefsDict(self.data), forKey: PrefStore.compatibleVersion)
+    }
+
+    self.subject.onNext(self.data)
+  }
+
+  private func prefDataFromDict(prefs: [String: AnyObject]) -> PrefData {
+    let defaultFontSize = NSNumber(float: Float(PrefStore.defaultEditorFont.pointSize))
+
+    let editorFontName = prefs[PrefKeys.editorFontName] as? String ?? PrefStore.defaultEditorFont.fontName
+    let editorFontSizeFromPref = prefs[PrefKeys.editorFontSize] as? NSNumber ?? defaultFontSize
+    let editorFontSize: CGFloat = CGFloat(editorFontSizeFromPref.floatValue) ?? CGFloat(defaultFontSize)
+
+    var editorFont = NSFont(name: editorFontName, size: editorFontSize) ?? PrefStore.defaultEditorFont
+    if !editorFont.fixedPitch {
+      editorFont = fontManager.convertFont(PrefStore.defaultEditorFont, toSize: editorFont.pointSize)
+    }
+    if editorFont.pointSize < PrefStore.minimumEditorFontSize
+      || editorFont.pointSize > PrefStore.maximumEditorFontSize {
+      editorFont = fontManager.convertFont(editorFont, toSize: CGFloat(defaultFontSize))
+    }
+
+    return PrefData(appearance: AppearancePrefData(editorFont: editorFont))
+  }
+
+  private func prefsDict(prefData: PrefData) -> [String: AnyObject] {
+    let appearanceData = prefData.appearance
+    let prefs: [String: AnyObject] = [
+        PrefKeys.editorFontName: appearanceData.editorFont.fontName,
+        PrefKeys.editorFontSize: appearanceData.editorFont.pointSize
+    ]
+    return prefs
+  }
+
+  private func addReactions() {
+    self.source
+      .filter { $0 is PrefData }
+      .map { $0 as! PrefData }
+      .subscribeNext { [unowned self] prefData in
+        self.data = prefData
+        self.userDefaults.setValue(self.prefsDict(prefData), forKey: PrefStore.compatibleVersion)
+        self.subject.onNext(prefData)
+      }
+      .addDisposableTo(self.disposeBag)
+  }
+}