Fernando Mendez Pinto is said to have been the first Westerner to set foot in Japan. Together with two other Portuguese, Christopher Borrello and Diego Zeimoto, he boarded a Chinese ship at Macao and, unable to make land on the Ryukyu Islands, they arrived on the island of Tanegashima, where they were carried by a storm. The governor of the island was impressed with their firearms (weapons he had never seen before) and had them studied and copied by Japanese craftsmen. This being the genesis of firearm-making in Japan, the weapons took the name of the island and were known as tanegashima (or teppo). This is earlier than most netsuke of the subject appearing on the market which are generally much taller, and made in the late 19th or early 20th century. Although the carving is of good quality and the piece is of some age, the artist appears to be unrecorded.
A similar netsuke signed Kosen is illustrated in Davey, N.K., Netsuke: A Study of the M.T. Hindson Collection, (London, 1974), p. 42, no. 88.