When you find many flowers at the entrance of an office building, hotel, restaurant or store like in the following pictures…
…the most likely reason is that a new business is being inaugurated or and existing one has relocated. Each flower pot is the present of a client or a business partner. If you can read some Japanese you can identify the name of the companies and the persons that sign the flowers. For example these flowers are a present of the president of Kadokawa:
Another curious thing is that you could guess how wealthy or powerful the company sending the flowers is just by spotting the biggest and most sumptuous flowers, which can cost as much as 1,000 EUR / 1,100 USD.
I found these flowers in this website, it is one of the standard models and costs around 250 EUR / 280 USD.
This one was sent by a board member of Fuji Xerox