Ginbu, from the word Genbu, is a guardian of the North. In Chinese and Japanese mythology, the four directions, East, South, West and North with China in the center, form the five cardinal points.
Each direction is represented by a celestial animal, the Dragon for the East, the Bird for the South, the Tiger for the West, and the Tortoise for the North.
The Tortoise (Genbu) represents endurance, wisdom, and longevity, and is also sometimes used in terms of divination. It is said the shell of the tortoise is the vault of the universe.