diff --git a/app/models/metadata_belongs_to.rb b/app/models/metadata_belongs_to.rb
index be1fa670..e1b84438 100644
--- a/app/models/metadata_belongs_to.rb
+++ b/app/models/metadata_belongs_to.rb
@@ -40,13 +40,21 @@ class MetadataBelongsTo < MetadataRelatedPosts
     # Si estamos cambiando la relación, tenemos que eliminar la relación
     # anterior
     if belonged_to.present?
-      belonged_to[inverse].value = belonged_to[inverse].value.reject do |rej|
-        rej == post.uuid.value
+      if belonged_to[inverse].respond_to? :has_one
+        belonged_to[inverse].value = nil
+      else
+        belonged_to[inverse].value = belonged_to[inverse].value.reject do |rej|
+          rej == post.uuid.value
+        end
       end
     end
 
     # No duplicar las relaciones
-    belongs_to[inverse].value = (belongs_to[inverse].value.dup << post.uuid.value) unless belongs_to.blank? || included?
+    if belongs_to[inverse].respond_to? :has_one
+      belongs_to[inverse].value = post.uuid.value
+    else
+      belongs_to[inverse].value = (belongs_to[inverse].value.dup << post.uuid.value) unless belongs_to.blank? || included?
+    end
 
     true
   end
diff --git a/app/models/metadata_has_one.rb b/app/models/metadata_has_one.rb
new file mode 100644
index 00000000..38911e1d
--- /dev/null
+++ b/app/models/metadata_has_one.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+class MetadataHasOne < MetadataHasMany
+  def had_one
+    return default_value if value_was.blank?
+
+    posts.find(uuid: value)
+  end
+
+  def has_one
+    return default_value if value.blank?
+
+    posts.find(uuid: value)
+  end
+
+  def had_many; end
+  def has_many; end
+
+  def save
+    super
+
+    return true unless changed?
+    return true unless inverse?
+
+    had_one&.value = nil
+    has_one&.value = post.uuid.value
+
+    true
+  end
+
+  def related_methods
+    @related_methods ||= %i[has_one had_one].freeze
+  end
+end
diff --git a/app/views/posts/attribute_ro/_has_one.haml b/app/views/posts/attribute_ro/_has_one.haml
new file mode 100644
index 00000000..c7e06be8
--- /dev/null
+++ b/app/views/posts/attribute_ro/_has_one.haml
@@ -0,0 +1,6 @@
+%tr{ id: attribute }
+  %th= post_label_t(attribute, post: post)
+  %td{ dir: dir, lang: locale }
+    - p = metadata.belongs_to
+    - if p
+      = link_to p.title.value, site_post_path(site, p.id)
diff --git a/app/views/posts/attributes/_has_one.haml b/app/views/posts/attributes/_has_one.haml
new file mode 100644
index 00000000..b0d21f35
--- /dev/null
+++ b/app/views/posts/attributes/_has_one.haml
@@ -0,0 +1,7 @@
+.form-group
+  = label_tag "#{base}_#{attribute}", post_label_t(attribute, post: post)
+  = select_tag(plain_field_name_for(base, attribute),
+    options_for_select(metadata.values, metadata.value),
+    **field_options(attribute, metadata), include_blank: t('.empty'))
+  = render 'posts/attribute_feedback',
+    post: post, attribute: attribute, metadata: metadata