Nalu Tanaka

A boy with a Japanese father who is a geophysicist and researcher, and a free-spirited Hawaiian mother. He is a family friend of the Hinaokas, and has known Masaki since childhood. He loves both surfing and his ukelele, and always rides the waves before going to school. Ever since Shou came and Masaki started surfing, the three of them have been waking up to surf in the early mornings.

(Source: Anime News Network)