"Japan blue" is a rich indigo blue dye that has been produced by dedicated craftsmen for centuries. Yoshino Chiba is one of those traditional artisans, who, at 85, has devoted more than 60 years to the craft. This fascinating documentary shows the whole process from production of the "indigo balls" to the final dyeing. We also meet other dedicated craftsmen such as Yoshino's daughter-in-law Matsue and pattern engraver Chuji Miura who help keep this ancient art alive.