The Samurai Jeans SIN25-01W Western Cut Flannel Shirt is a bold expression of the brand’s uncompromising approach to fabric development, blending rope-dyed indigo yarns traditionally used for denim with the warmth and softness of heavyweight flannel. Crafted in Japan from Samurai’s original 12oz heavy flannel, this shirt bridges the worlds of denim and classic workwear in a truly distinctive way.

The fabric combines dark indigo rope-dyed yarns with specially dyed reactive-color threads that fade naturally over time. The result is a flannel that behaves much like denim—developing depth, contrast, and character with wear—while retaining the rich, multi-tonal appearance unique to flannel checks. As the indigo ages, the shirt reveals brighter blues and subtle black-lined contrast, creating a highly personal patina unique to each wearer.

Woven from dense, slubby cotton yarns more commonly associated with denim, the fabric has a tactile, almost handwoven feel that reinforces Samurai’s reputation for rugged textures and longevity. At 12oz, it offers substantial warmth and structure without sacrificing comfort, making it ideal for colder seasons or layering as a light overshirt.

Construction details are executed to Samurai’s exacting standards. The shirt features triple chain-stitched run-off side seams, reinforced double-fabric forearms for added durability, and cotton lining at the cuffs, collar, and button placket to enhance strength and wear resistance. Indigo-dyed nut buttons add a subtle, traditional finish, while the Western-style cut and symmetrical chest pockets maintain a clean, balanced silhouette. A pencil slot in the right pocket and the iconic Samurai Union Ticket complete the garment.

Fit Notes: Although this is a Japanese-made shirt, we carry the Western-cut version of Samurai flannels, which fits closer to standard Western sizing. If you typically wear a size M in American shirts, a size M should fit well here. As always, we recommend consulting our size chart to ensure the best possible fit.