Concepts like sending letters to the future cannot be patented.

The trademark "Cat's Sky City" was filed for trademark registration by a company in Changshu and is currently in the opposition process.

As long as you don’t use the same name, and don’t use the other party’s related pictures and information that may infringe copyright, you can open a store that is destined for the future.

In order to avoid encountering trademark problems like Cat’s Sky City, it is recommended that you apply for trademark registration as soon as you decide on the store name.

About the supplementary question:

That is a utility model related to a letter rack. This cannot be evaluated or cracked by colleagues acting as agents. Go to the State Intellectual Property Bureau and take a look at the next copy of 201020254370.