Nikkei 225 and Gold

Below are the screen shot for Nikkei 225 and Reverse Chart for Gold.

My thought are:

"Is Gold React to N225 or N225 react to Gold"

"Which one is the manipulated variable and responding variable"

or

"Is there any third party that cause the chart looks almost counter similar; ( The reverse for N225 = Gold)"

Gold is very low as this post is written.