Sago New Material Guitars is a custom electric guitar and bass workshop based in Amagasaki, Hyogo, Japan, founded in 2004 by Takayama Satoshi. The company operates as a made-to-order studio where luthiers build each instrument largely by hand — from rough wood through painting and assembly — with customers specifying shape, scale, wood, finish, and hardware. Alongside fully custom builds, Sago offers body, neck, and pickguard fabrication, refinishing, and refret work.

The company houses several sub-brands: Sago is the flagship high-end custom line, Stem sits alongside it as a workshop brand, Seed is a lower-cost line that produces Sago artist signature models through overseas factories, and L(x) is their in-house pickup brand. Sago is known for experimenting with unusual tonewoods and construction methods, including thermo-treated wood and carbon-reinforced necks, and for instruments that incorporate Japanese design motifs such as sakura (cherry blossom) inlays and finishes.

Sago has built a reputation in the Japanese session and progressive music scenes for close artist collaborations and signature models, and regularly exhibits at industry events such as the NAMM Show. The brand is sold direct and through retailers like Reverb, with a particular following among bass players seeking boutique Japanese instruments.

Sago has 14 products cataloged on Equipboard, including Solid Body Electric Guitars and Electric Basses. Their gear is featured by 6 artists, with the strongest followings in Rock, Pop, and Metal. Notable users include Machiya, Ami Kusakari, and Kosuke Tano.