Tokyo Kaioi 東京貝覆い

The Tokyo metropolitan symbol mark seen in the street fence in Tokyo. This is that the ginkgo is a motif, but it looks like a shell. Let’s play Kaioi with the shells scattered in Tokyo.
Kaioi is an aristocratic play of the Heian period. In a modern memory game, we divide bivalves into two and find a pair of shells. The same picture and the corresponding picture were drawn on the inside of a pair of shellfish.
Why do not you take a walk in Tokyo to find a pair of shellfish? The scenery in the picture and the address of the title are hints.