Tokyo introduction

This is a monument of a dragon located near Exit 2 of Tatsumi Station on the Yurakucho Subway Line.
The dragon in "Tatsu" means dragon.
"Mi" means snake.
These are the animals that appear in the Chinese zodiac.
In Japan, the 12 animals in the Chinese zodiac are sometimes arranged like a clock to show the direction.
Tatsumi is located in the direction of Tatsumi as seen from Edo Castle, hence the name Tatsumi.

Wikipedia

Sexagenary cycle
https://en.wikipedia.org/wiki/Sexagenary_cycle