The scale is also called "yona nuki" scale, meaning the scale omitting yon (meaning four in Japanese) and nana (meaning seven in Japanese), because the pentatonic scale uses five notes by removing fourth and seventh notes from the Western scale of seven notes and using the fifth and sixth notes of the Western scale as the fourth and fifth notes respectively.
すなわち、西洋音楽の7音階から第4音と第7音を外し、第5音と第6音をそれぞれ第4音と第5音にする五音音階を使用することから、4と7を抜くヨナ抜き音階と呼ばれる音階法である。