diff --git a/lib/relation-definition.js b/lib/relation-definition.js
index 84ebc44e..63592e8c 100644
--- a/lib/relation-definition.js
+++ b/lib/relation-definition.js
@@ -20,6 +20,7 @@ var RelationTypes = {
   hasOne: 'hasOne',
   hasAndBelongsToMany: 'hasAndBelongsToMany',
   referencesMany: 'referencesMany',
+  embedsOne: 'embedsOne',
   embedsMany: 'embedsMany'
 };
 
@@ -30,6 +31,7 @@ exports.HasOne = HasOne;
 exports.HasAndBelongsToMany = HasAndBelongsToMany;
 exports.BelongsTo = BelongsTo;
 exports.ReferencesMany = ReferencesMany;
+exports.EmbedsOne = EmbedsOne;
 exports.EmbedsMany = EmbedsMany;
 
 var RelationClasses = {
@@ -39,6 +41,7 @@ var RelationClasses = {
   hasOne: HasOne,
   hasAndBelongsToMany: HasAndBelongsToMany,
   referencesMany: ReferencesMany,
+  embedsOne: EmbedsOne,
   embedsMany: EmbedsMany
 };
 
@@ -384,6 +387,24 @@ function HasOne(definition, modelInstance) {
 
 util.inherits(HasOne, Relation);
 
+/**
+ * EmbedsOne subclass
+ * @param {RelationDefinition|Object} definition
+ * @param {Object} modelInstance
+ * @returns {EmbedsMany}
+ * @constructor
+ * @class EmbedsOne
+ */
+function EmbedsOne(definition, modelInstance) {
+  if (!(this instanceof EmbedsOne)) {
+    return new EmbedsMany(definition, modelInstance);
+  }
+  assert(definition.type === RelationTypes.embedsOne);
+  Relation.apply(this, arguments);
+}
+
+util.inherits(EmbedsOne, Relation);
+
 /**
  * EmbedsMany subclass
  * @param {RelationDefinition|Object} definition
@@ -1539,6 +1560,170 @@ HasOne.prototype.related = function (refresh, params) {
   }
 };
 
+RelationDefinition.embedsOne = function (modelFrom, modelTo, params) {
+  params = params || {};
+  modelTo = lookupModelTo(modelFrom, modelTo, params);
+
+  var thisClassName = modelFrom.modelName;
+  var relationName = params.as || (i8n.camelize(modelTo.modelName, true) + 'Item');
+  var propertyName = params.property || i8n.camelize(modelTo.modelName, true);
+  var idName = modelTo.dataSource.idName(modelTo.modelName) || 'id';
+  
+  if (relationName === propertyName) {
+    propertyName = '_' + propertyName;
+    debug('EmbedsOne property cannot be equal to relation name: ' +
+      'forcing property %s for relation %s', propertyName, relationName);
+  }
+  
+  var definition = modelFrom.relations[relationName] = new RelationDefinition({
+    name: relationName,
+    type: RelationTypes.embedsOne,
+    modelFrom: modelFrom,
+    keyFrom: propertyName,
+    keyTo: idName,
+    modelTo: modelTo,
+    multiple: false,
+    properties: params.properties,
+    scope: params.scope,
+    options: params.options,
+    embed: true
+  });
+  
+  var opts = { type: modelTo };
+  
+  if (params.default === true) {
+    opts.default = function() { return new modelTo(); };
+  } else if (typeof params.default === 'object') {
+    opts.default = (function(def) {
+      return function() { return new modelTo(def); };
+    }(params.default));
+  }
+  
+  modelFrom.dataSource.defineProperty(modelFrom.modelName, propertyName, opts);
+  
+  // validate the embedded instance
+  if (definition.options.validate) {
+    modelFrom.validate(relationName, function(err) {
+      var inst = this[propertyName];
+      if (inst instanceof modelTo) {
+        if (!inst.isValid()) {
+          var first = Object.keys(inst.errors)[0];
+          var msg = 'is invalid: `' + first + '` ' + inst.errors[first];
+          this.errors.add(relationName, msg, 'invalid');
+          err(false);
+        }
+      }
+    });
+  }
+  
+  // Define a property for the scope so that we have 'this' for the scoped methods
+  Object.defineProperty(modelFrom.prototype, relationName, {
+    enumerable: true,
+    configurable: true,
+    get: function() {
+      var relation = new EmbedsOne(definition, this);
+      var relationMethod = relation.related.bind(relation)
+      relationMethod.create = relation.create.bind(relation);
+      relationMethod.build = relation.build.bind(relation);
+      relationMethod.destroy = relation.destroy.bind(relation);
+      relationMethod._targetClass = definition.modelTo.modelName;
+      return relationMethod;
+    }
+  });
+  
+  // FIXME: [rfeng] Wrap the property into a function for remoting
+  // so that it can be accessed as /api/<model>/<id>/<embedsOneRelationName>
+  // For example, /api/orders/1/customer
+  var fn = function() {
+    var f = this[relationName];
+    f.apply(this, arguments);
+  };
+  modelFrom.prototype['__get__' + relationName] = fn;
+  
+  return definition;
+};
+
+EmbedsOne.prototype.related = function (refresh, params) {
+  var modelTo = this.definition.modelTo;
+  var modelInstance = this.modelInstance;
+  var propertyName = this.definition.keyFrom;
+  
+  if (arguments.length === 1) {
+    params = refresh;
+    refresh = false;
+  } else if (arguments.length > 2) {
+    throw new Error('Method can\'t be called with more than two arguments');
+  }
+  
+  if (params instanceof ModelBaseClass) { // acts as setter
+    if (params instanceof modelTo) {
+      this.definition.applyProperties(modelInstance, params);
+      modelInstance.setAttribute(propertyName, params);
+    }
+    return;
+  }
+  
+  var embeddedInstance = modelInstance[propertyName];
+  if (typeof params === 'function') { // acts as async getter
+    var cb = params;
+    process.nextTick(function() { 
+      cb(null, embeddedInstance);
+    });
+  } else if (params === undefined) { // acts as sync getter
+    return embeddedInstance;
+  }
+};
+
+EmbedsOne.prototype.create = function (targetModelData, cb) {
+  var modelTo = this.definition.modelTo;
+  var propertyName = this.definition.keyFrom;
+  var modelInstance = this.modelInstance;
+  
+  if (typeof targetModelData === 'function' && !cb) {
+    cb = targetModelData;
+    targetModelData = {};
+  }
+  
+  targetModelData = targetModelData || {};
+  
+  var inst = this.build(targetModelData);
+  
+  var err = inst.isValid() ? null : new ValidationError(inst);
+  
+  if (err) {
+    return process.nextTick(function() {
+      cb(err); 
+    });
+  }
+  
+  modelInstance.updateAttribute(propertyName, 
+    inst, function(err) {
+    cb(err, err ? null : inst);
+  });
+};
+
+EmbedsOne.prototype.build = function (targetModelData) {
+  var modelTo = this.definition.modelTo;
+  var modelInstance = this.modelInstance;
+  
+  targetModelData = targetModelData || {};
+  
+  this.definition.applyProperties(modelInstance, targetModelData);
+  
+  return new modelTo(targetModelData);
+};
+
+EmbedsOne.prototype.destroy = function (cb) {
+  var modelInstance = this.modelInstance;
+  var propertyName = this.definition.keyFrom;
+  modelInstance.unsetAttribute(propertyName, true);
+  if (typeof cb === 'function') {
+    modelInstance.save(function(err) {
+      cb(err);
+    });
+  }
+};
+
 RelationDefinition.embedsMany = function embedsMany(modelFrom, modelTo, params) {
   params = params || {};
   modelTo = lookupModelTo(modelFrom, modelTo, params, true);
@@ -1602,7 +1787,7 @@ RelationDefinition.embedsMany = function embedsMany(modelFrom, modelTo, params)
             var id = item[idName] || '(blank)';
             var first = Object.keys(item.errors)[0];
             var msg = 'contains invalid item: `' + id + '`';
-            msg += ' (' + first + ' ' + item.errors[first] + ')';
+            msg += ' (`' + first + '` ' + item.errors[first] + ')';
             self.errors.add(propertyName, msg, 'invalid');
           }
         } else {
@@ -1716,15 +1901,11 @@ EmbedsMany.prototype.related = function(receiver, scopeParams, condOrRefresh, cb
   var modelInstance = this.modelInstance;
   
   var actualCond = {};
-  var actualRefresh = false;
   if (arguments.length === 3) {
     cb = condOrRefresh;
   } else if (arguments.length === 4) {
-    if (typeof condOrRefresh === 'boolean') {
-      actualRefresh = condOrRefresh;
-    } else {
+    if (typeof condOrRefresh === 'object') {
       actualCond = condOrRefresh;
-      actualRefresh = true;
     }
   } else {
     throw new Error('Method can be only called with one or two arguments');
@@ -1923,7 +2104,7 @@ EmbedsMany.prototype.build = function(targetModelData) {
     }
   }
   
-  this.definition.applyProperties(this.modelInstance, targetModelData);
+  this.definition.applyProperties(modelInstance, targetModelData);
   
   var inst = new modelTo(targetModelData);
   
diff --git a/lib/relations.js b/lib/relations.js
index ba9a36d7..790433fc 100644
--- a/lib/relations.js
+++ b/lib/relations.js
@@ -158,14 +158,18 @@ RelationMixin.hasAndBelongsToMany = function hasAndBelongsToMany(modelTo, params
   return RelationDefinition.hasAndBelongsToMany(this, modelTo, params);
 };
 
-RelationMixin.hasOne = function hasMany(modelTo, params) {
+RelationMixin.hasOne = function hasOne(modelTo, params) {
   return RelationDefinition.hasOne(this, modelTo, params);
 };
 
-RelationMixin.referencesMany = function hasMany(modelTo, params) {
+RelationMixin.referencesMany = function referencesMany(modelTo, params) {
   return RelationDefinition.referencesMany(this, modelTo, params);
 };
 
-RelationMixin.embedsMany = function hasMany(modelTo, params) {
+RelationMixin.embedsOne = function embedsOne(modelTo, params) {
+  return RelationDefinition.embedsOne(this, modelTo, params);
+};
+
+RelationMixin.embedsMany = function embedsMany(modelTo, params) {
   return RelationDefinition.embedsMany(this, modelTo, params);
 };
diff --git a/test/relations.test.js b/test/relations.test.js
index 871ecb54..564102cb 100644
--- a/test/relations.test.js
+++ b/test/relations.test.js
@@ -1320,6 +1320,131 @@ describe('relations', function () {
     });
   });
   
+  describe('embedsOne', function () {
+    
+    var person;
+    var Other;
+    
+    before(function () {
+      db = getSchema();
+      Person = db.define('Person', {name: String});
+      Passport = db.define('Passport', 
+        {name:{type:'string', required: true}}, 
+        {idInjection: false}
+      );
+      Other = db.define('Other', {name: String});
+    });
+
+    it('can be declared using embedsOne method', function () {
+      Person.embedsOne(Passport, {
+        default: {name: 'Anonymous'}, // a bit contrived
+        options: {validate: true}
+      });
+    });
+    
+    it('should have setup a property and accessor', function() {
+      var p = new Person();
+      p.passport.should.be.an.object; // because of default
+      p.passportItem.should.be.a.function;
+      p.passportItem.create.should.be.a.function;
+      p.passportItem.build.should.be.a.function;
+      p.passportItem.destroy.should.be.a.function;
+    });
+    
+    it('should return an instance with default values', function() {
+      var p = new Person();
+      p.passport.toObject().should.eql({name: 'Anonymous'});
+      p.passportItem().should.equal(p.passport);
+      p.passportItem(function(err, passport) {
+        should.not.exist(err);
+        passport.should.equal(p.passport);
+      });
+    });
+    
+    it('should embed a model instance', function() {
+      var p = new Person();
+      p.passportItem(new Passport({name: 'Fred'}));
+      p.passport.toObject().should.eql({name: 'Fred'});
+      p.passport.should.be.an.instanceOf(Passport);
+    });
+    
+    it('should not embed an invalid model type', function() {
+      var p = new Person();
+      p.passportItem(new Other());
+      p.passport.toObject().should.eql({name: 'Anonymous'});
+      p.passport.should.be.an.instanceOf(Passport);
+    });
+    
+    it('should create an embedded item on scope', function(done) {
+      Person.create({name: 'Fred'}, function(err, p) {
+        should.not.exist(err);
+        p.passportItem.create({name: 'Fredric'}, function(err, passport) {
+          should.not.exist(err);
+          p.passport.toObject().should.eql({name: 'Fredric'});
+          p.passport.should.be.an.instanceOf(Passport);
+          done();
+        });
+      });
+    });
+    
+    it('should get an embedded item on scope', function(done) {
+      Person.findOne(function(err, p) {
+        should.not.exist(err);
+        var passport = p.passportItem();
+        passport.toObject().should.eql({name: 'Fredric'});
+        passport.should.be.an.instanceOf(Passport);
+        passport.should.equal(p.passport);
+        done();
+      });
+    });
+    
+    it('should validate an embedded item on scope - on creation', function(done) {
+      var p = new Person({name: 'Fred'});
+      p.passportItem.create({}, function(err, passport) {
+        should.exist(err);
+        err.name.should.equal('ValidationError');
+        var msg = 'The `Passport` instance is not valid.';
+        msg += ' Details: `name` can\'t be blank.';
+        err.message.should.equal(msg);
+        done();
+      });
+    });
+    
+    it('should validate an embedded item on scope - on update', function(done) {
+      Person.findOne(function(err, p) {
+        var passport = p.passportItem();
+        passport.name = null;
+        p.save(function(err) {
+          should.exist(err);
+          err.name.should.equal('ValidationError');
+          var msg = 'The `Person` instance is not valid.';
+          msg += ' Details: `passportItem` is invalid: `name` can\'t be blank.';
+          err.message.should.equal(msg);
+          done();
+        });
+      });
+    });
+    
+    it('should destroy an embedded item on scope', function(done) {
+      Person.findOne(function(err, p) {
+        p.passportItem.destroy(function(err) {
+          should.not.exist(err);
+          should.equal(p.passport, null);
+          done();
+        });
+      });
+    });
+    
+    it('should get an embedded item on scope - verify', function(done) {
+      Person.findOne(function(err, p) {
+        should.not.exist(err);
+        should.equal(p.passport, null);
+        done();
+      });
+    });
+    
+  });
+  
   describe('embedsMany', function () {
     
     var address1, address2;
@@ -1591,7 +1716,7 @@ describe('relations', function () {
       Person.create({ name: 'Wilma', addresses: addresses }, function(err, p) {
         err.name.should.equal('ValidationError');
         var expected = 'The `Person` instance is not valid. ';
-        expected += 'Details: `addresses` contains invalid item: `work` (street can\'t be blank).';
+        expected += 'Details: `addresses` contains invalid item: `work` (`street` can\'t be blank).';
         err.message.should.equal(expected);
         done();
       });