Rock found in Tokyo

Hi, I am Mira from Germany and last week I found one of your rocks in Tokyo. I was there on holiday with my father and it was our last day in Tokyo. We wanted to take photos at the Shibuya crossing when I spotted this stone. At first I thought that somenone had lost his souvenir. I wanted to have a closer look, so I took it and then I saw that there was written: It´s yours. 
At that point I was happy because actually that is my only souvenir from Tokyo. 
But I was also wondering what wordrocks is. 
Back at the hotel I looked it up in the internet. I think wordrocks is a great idea and I decided to take the rock with me onto Mt. Fuji where we went the next day to see the sunrise. This is where the photographs were taken.
I also read that the cherry tree, Sakura, symbolizes beauty, starting and evanescence which really represents our situation at that time, because our trip was nearly over but we also climbed onto Mt. Fuji which was very great and to see the sunrise from up there was one of the most beautiful things I have ever seen, but a sunrise is very ephemeral.
I took the stone back to Germany and I will keep it as memory of our great trip to Japan and the beauty, but also the evanescence of everything.
Thank you very much for that,