wehewehe.org gives us this definition:
naʻau
n. Intestines, bowels, guts; mind, heart, affections; of the heart or mind; mood, temper, feelings.
Na`au, also know in various places as the chi, ki, or prana, is located below the piko (belly button). It houses our mana (power), and is the essence of our very being. When I write from the na`au, I write my truth. I write what’s raw, meaningful, powerful, and passionate to me. The na`au goes beyond the heart and deep down into our power house and brings to the surface the words that our minds are too fearful to write.
He mele mai ka na`au = the song from the na`au
This blog is dedicated to writing from my na`au and producing creative work that hopefully inspires others.
From The Na`au of A Mermaid 
Hi Riss. This is all new to me.Mom showed me this site. Never knew this existed. I am impressed by your passion for putting your emotions to ink ; although I am not surprised. Remember your body may be the representation of the sum total of your life’s experiences ,but the mind determines the quality of those experiences. Love dad.