At the end of the Edo period, the Edo bakufu (Japanese feudal government headed by a shogun) and its domains were forced to eliminate their 'matchlock infantry' armed with matchlocks and to form a 'musket infantry' or 'musket unit' armed with Western style firearms, however, the number of ashigaru (common foot soldiers) was sometimes not enough to form these infantries or units and, in these cases, new members were recruited to create a musket infantry similar to the ashigaru troops in the Sengoku Period (Period of Warring States).
幕末になって江戸幕府及び諸藩は、火縄銃装備の「鉄砲組」を廃止し、洋式銃装備の「歩兵隊」や「銃隊」を作る必要に迫られたが、従来の足軽身分のものだけでは不十分なケースが多々見られ、こうした場合、新たに人員を募集し戦国時代の足軽隊に似た歩兵部隊を創設することがあった。