Elements, in this case the four classic ones in western cultures(earth, air, water and fire), are strictly connected with each other, in a balance that´s the basis of everything. The symbols inside this design are the symbols of the 4 elements themselves. This version is particularly fit for irezumi styled colouring.
This design was inspired by the request of a user.
A curiosity: in chinese culture, the main elements are five, and they are earth, metal, water, wood and fire.