Kotaro Oshio "Wing" Series Naga Guitars is designed and handmade by a famous Chinese luthier, the founder of the Fibonacci Guitars, Wang Zi Yuan. The tone, strings action, outlook design as well as the colours of the hard case,  are all chosen by Kotaro Oshio himself. Wang Zi Yuan has made the guitar come alive. 

The top of the guitars uses the 5A Sitka Spruce which had been through the natural drying for more than 5 years, same goes to the wild Indian Rosewood for the side and back. There are two models, one with cutaway and one without cutaway.