Nalu apparently means wave in Hawaiian, but in this case its a company based in Los Angeles, California founded in 2011 who market 4 ranges of, (very expensive for a Chinese import), Ukulele with a laser etched wave motif on the sound hole. 

The ranges are: Ahua - Simple solid mahogany with few embellishments, PPS nut and saddle. All acoustic with a matte finish, in Soprano, Concert, Superconcert or Tenor Scale. 

Hokua - Mahogany with binding and lots of inlay, Black Tusq nut and saddle. Can be acoustic or electro-acoustic (with a cutaway), gloss or matte finish and comes in Soprano, Concert, Superconcert or Tenor Scale.

Kaiko’o - Sitka Spruce top with Zebrawood back and sides, binding, and lots of inlay. Can be acoustic or electro-acoustic, (with a cutaway), a black gloss finish and comes in Concert, Superconcert or Tenor ScalePapakea - Sitka Spruce top with Rosewood back and sides; and a Maple fretboard. Acoustic or electro-Acoustic, Superconcert Tenor or Baritone, pin bridge and no fret markers beyond the 7th fret logo.

They ceased trading around 2020 having ceased importing a couple of years previous and just sold off remaining stock

 One extra for the money though is they promised to send the owner a new set of strings every year (They never did for me though and obviously don't now).