Dragonfly is a Japanese custom guitar and bass brand established in 1999 by luthier Tatsuaki Totani, operated under his company Harry's Engineering. Before founding the brand, Totani spent the 1980s as a master builder at Aria Pro II before launching his own instrument workshop in 1991. Based in Japan, the company builds largely to order with a small team, and the brand has stayed primarily focused on the Japanese domestic market rather than international distribution.

The lineup spans six- and seven-string electric guitars as well as four-, five-, and six-string basses, including series such as the CS, Border, and Hi-Standard. Dragonfly is particularly associated with its 666mm scale length, a specification adapted from classical guitar tradition that the brand uses to suit downtuned playing styles. Instruments emphasize hand selection of tonewoods, neck-through and bolt-on builds, and high-end hardware, with pricing positioned in the custom/boutique tier.

The brand has attracted a following among heavier-music players in Japan — including guitarists Pablo and Enryu — and the 666-related specs have helped build a niche reputation among metal and extended-range enthusiasts. Outside Japan, Dragonfly's visibility is largely driven by collector interest, secondary-market listings on Reverb, and word of mouth on forums such as SevenString.org and TalkBass.

Dragonfly has 7 products cataloged on Equipboard, including Reverb Plugins, Distortion Effects Pedals, and Electric Basses. Their gear is featured by 2 artists, with the strongest followings in Rock and Electronic. Notable users include Die and Kaoru.