One Piece of Rock is a Japanese heritage denim brand founded by Yoshiaki Konaka and produced at the Conners Sewing Factory in Shiga Prefecture, Japan. The label is dedicated to recreating the spirit and craftsmanship of early 20th-century American workwear—particularly the “golden age” of denim from roughly 1900 to the 1940s—through meticulously handcrafted jeans and jackets made with selvedge denim from Japan’s renowned denim region of Kojima, Okayama. Using restored vintage sewing machines and historically informed techniques, One Piece of Rock focuses on small-batch production and extreme attention to detail, blending vintage inspiration with contemporary Japanese monozukuri craftsmanship to create garments designed to embody the authenticity and character of classic American denim.