Masao is a distinctive boys' name in United States, ranking #13364 in 2013 with 5 recorded births. This places Masao in the bottom 5% of ranked US boys' names for the year. Its actual usage is classified as Rare. The name reached its all-time peak in 2011 with 8 births ranking #9319. In 2013, approximately 1 in every 378,251 boys born was named Masao. FALLING Recent data shows the name is currently falling.