Chokin is a technique used to decorate and embellish a metal article by carving and embossing it with a chisel. It is said that chokin originated as far back as the Kofun period, when techniques such as 'kebori' (fine line carving) and 'sukashibori' (carved openwork) were skillfully and elaborately used to create accessories and so on.

After the Muromachi period, as the crafts for sword-related equipment flourished, chokin metalworking techniques and technology also developed.

At the beginning of the Meiji period, the passing of the Haito-rei law (banning swords in public) led the way for the chokin technique to be used to make accessories and so forth instead. This laid the foundation for the chokin technique seen today.

Mitsuo Masuda (born 1909 and still alive today) is a designated holder of an important intangible cultural property (Living National Treasure) of metal carving. After graduating from the chokin section of the Metal Works Department of Tokyo Art University, Masuda became a pupil of Kenkichi Tomimoto and brought many superb creations into the world.

The most notable feature of Masuda's work are the references to nature in his carved patterns, resulting in carvings that are rich in the sense of the season.

It is said that his plated and gilded creations in particular receive high acclaim and praise. Masuda's bold yet eloquent works show an aesthetic sense of beauty that has been refined over 70 years.