Gargron

This widget shows all tags that are anime titles as a dropdown menu. It creates a taxonomy called Anime, you only need to tag your posts not in the ‘Post Tags’ box, but the ‘Anime’ box.

Anime Dropdown Widget

This widget shows all tags that are anime titles as a dropdown menu. Using WordPress' custom taxonomies.

Marzio Carro

Adds categories and tags functionality for your pages.
This plugin addsthe ‘post_tag’ and the ‘category’ taxonomies, which are the names of the existing taxonomies used for tags and categories the Post type ‘page’.
This enables the categories metabox and the tags metabox in the New or Edit Page interface.
The plugin has no settings, does not alter the database and only uses hooks to 
achieve it’s goal. It works perfectly fine with Multisite installations.
This plugin WILL NOT add any display of categories or tags to your template files.
Plugin’s website: <a href="http://technotes.marziocarro.com/category/wordpress-plugins/" rel="nofollow ugc">http://technotes.marziocarro.com/category/wordpress-plugins/</a>
Author’s website: <a href="http://technotes.marziocarro.com/" rel="nofollow ugc">http://technotes.marziocarro.com/</a>

Category Tag Pages

Wonderful functionality

Yes, it works. Uses very few lines of code and it's a simple and safe solution to have categories and tags in pages.

It works

Adds categories and tags functionality for your pages.

Anime Dropdown Widget vs Category Tag Pages