What is a secret? What's there to hide? What's something other people shouldn't know? Or, something secret?
A secret is something that is deliberately hidden so that others do not know it; or, something that no one can or is difficult to know and understand.
For this game also has a secret too. There are 2 ways to find out the secret's existence.
The first is visible to the eye. For example, a book on a shelf. Have you ever seen different, unordered books on the shelf? What would you do if you saw him? If it were me, I would definitely pull out the book and move it to a suitable shelf. However, when I pulled out, a secret door suddenly opened. So, the book is a key to discovering a secret. That is the secret that can be seen by the eye.
