Einosuke Murakami, a researcher interested in the history of steel manufacturing in Japan, notes that one can see two paths for the development of bellows around the world. One he describes as that of the saucer-style bellows found in the southern culture regions, including the ancient Orient and India. The other is the leather bellows found in the ancient northern cultural sphere. The Zhongyuan region of China is part of this latter group. The pump bellows was developed in the cultural border-crossing zone that stretches from this area in southern China to the Indochina Peninsula, a development that incorporated elements of bamboo tool-making culture into the leather bellows. This, it is hypothesized, may have been a step on the road to the development of the fukisashi bellows. In Japan, the bellows used for iron manufacturing in ancient times shifted over time from the leather bellows to the foot bellows, but by the medieval period it is the fukisashi bellows (a box-type air-pump) that become common. However, there were iron-manufacturing sites that continued to the foot bellows until early modern times, and the use of both foot bellows and fukisashi bellows persisted in iron-manufacturing use until the invention of the tenbin-fuigo at the end of the 17th century.