The Deluxeware S101-00 Flat Seam Plain Sweatshirt is a fully Japanese-made sweatshirt developed as a modern evolution of classic American athletic wear from the mid-20th century. Drawing inspiration from sweatshirts that emerged between the 1930s and 1950s, Deluxeware focuses not only on visual authenticity, but on the functional qualities, fabric integrity, and construction methods that defined the originals.

At the core of this sweatshirt is an exceptionally dense 20oz loopwheel fleece, knitted on vintage 吊編機 (tsuri-ami) circular knitting machines in Wakayama Prefecture. These machines operate at extremely low speeds, relying on gravity rather than tension, allowing the fabric to be knitted at its maximum density without internal stress. The result is a sweatshirt fabric with a dry, firm hand feel, outstanding heat retention, and remarkable durability. The interior is brushed for warmth, creating a balance of rugged exterior texture and comfortable insulation.

The sewing is carried out in Odate, Akita Prefecture, using original 1950s Union Special flat seamer machines. This flat seam construction minimizes bulk, improves comfort against the skin, and significantly increases seam strength—one of the defining characteristics of true vintage athletic garments.

Featuring a classic set-in sleeve design and a plain, no-nonsense silhouette, the S101-00 represents Deluxeware’s philosophy of refining a standard rather than reinventing it. The brand refers to this series as its “Emotional Standard”—a garment that delivers lasting satisfaction through material quality, craftsmanship, and long-term wear rather than trend-driven design.

Fit Notes: Deluxeware sweats tend to run small compared to American sizing. Because of their Japanese sizing, we usually recommend going up one or even two sizes. In addition, Deluxeware always offers USM and USL sizes, which are larger than XL and feature a more regular, less tailored cut. For the best fit, we always recommend checking the size chart before choosing your size.