I've only been playing this game for about a week, and ever since the first day I've been getting these manyu in my gift box. Doing what only seemed obvious, I took them out of the gift box. After a bit of not even thinking about them, I just went to try and use them, and for the love of me I can't figure out how to use them, let alone find out where they are stored. So any insight would be helpful...

Please note... I looked on the wiki and googled this a few times already to no avail, the only thing I learned was that they are used for XP.