Ichiryo Gusoku (一領具足)

Ichiryo gusoku (literally means a set of armor) was a designation for a part time soldier and farmer and their organization (in sociology) which was formed and managed by Chosokabe clan, the daimyo (Japanese territorial lord) of Tosa Province in the Sengoku period targeting on armed peasants and jizamurai (local samurai) before heinobunri (a policy to strictly separate soldiers and farmers). Tosa Monogatari described it as fearless wandering samurai.

Summary
In peacetime, Ichiryo gusoku lived as farmers engaged in working the land, however, once they were mobilized by the feudal lord, they were supposed to respond it at once with ichiryo (one set) of gusoku (weapon, armor). To respond a sudden call-up without delay, they always carried their spear and armor during their farm working, thus they called Ichiryo gusoku. Another reason for this designation was that they could not afford to have extra sets of armor and had only a set of armor, while regular samurai had two sets of armor including a spare set. Since they were such part-time soldiers, Ichiryo gusoku were exempted tasks obligated to ordinary samurai.

As they were engaged in farm working, many of them were robust and had aptitude for group work, accordingly they were considered to have been high-leveled soldiers. However, in the nature that they were concurrently farmers, it is considered to be hard to mobilize them during the busiest farming season and thus it was impossible to make them fight battles over a long period of time.

History
Ichiryo gusoku was invented by Kunichika CHOSOKABE (Other theory says it was invented by his vassal, Takayori YOSHIDA.). It was Motochika CHOSOKABE, the son of Kunichika, who made use of Ichiryo gusoku eagerly and effectively. Motochika, leading powerful Ichiryogusoku, achieved the unification of Shikoku region, however, the territory was reduced to only Tosa Province due to Hideyoshi TOYOTOMI's Shikoku Conquest. Further, in the subsequent Battle of Sekigahara, Motochika's forth son, Morichika CHOSOKABE who took over head of the family, joined the Western Camp, leading to confiscation of shoryo (territory) and Kaieki (forfeit rank of Samurai and properties) after the war.

Katsutoyo YAMAUCHI was given the Tosa Domain as the successor of the Chosokabe family, however, the remnant corps of the Chosokabe family did not necessarily welcomed the new lord. Soemon TAKEUCHI and his Ichiryo gusoku members refused to hand over the Urato-jo Castle and demanded that Morichika should be given a part of the old territory, or 'half land of Tosa'; this is called 'Urado riot'. Katsutoyo YAMAUCHI sent his younger brother, Yasutoyo YAMAUCHI, to suppress it. The remnant corps resisted this by holding the Urato-jo Castle, but eventually surrendered the castle and capitulated due to an act of treachery from within the castle. 273 members of Ichiryo gusoku were reported to be decapitated and their heads were salted to send to Naomasa II in Osaka.

After that, Ichiryo gusoku incited rebellion, such as Takiyama Riot led by Samanosuke TAKAISHI. The Yamanouchi clan suppressed them and put what remained of the Chosokabe corps, including Ichiryo gusoku, under its control, giving them the rank of goshi (country samurai), which was a rank below that of a Joshi (upper-level feudal retainer of a daimyo). In Tosa Province, goshi was strictly distinguished from feudal retainer of domain, creating conflicts between the superior and inferior throughout the Edo Period.

Equipment of the Ichiryo gusoku (military uniform of Chosokabe troops)
head-shaped helmet (the earlier style)
kasajigoro (a straw-hat-shaped neck guard)
under armour
short sword
waist strap
drawers