The Shichinintai were a group of seven soldiers out for hire. They only work for themselves, and wandered everywhere taking up work. In terms of their strength, those seven could do what a hundred soldiers are capable of. However, their killing methods were too cruel. It seemed that they enjoy killing people, they either chop people’s heads off, or burn them alive.
	However, the feudal lords feared that they would wrecked havoc, thus they seek to subdue the Shichinintai. The Shichinintai made their escape into the mountains. They were outnumbered.
	After a long struggle, they were finally captured in a village in the north. All their heads were chopped off and they were buried.
	Nevertheless, the local people feared a curse and wanted to appease the souls of the Shichinin. Hence, they erected the Shichinin grave at the base of the Mount Hakurei [白霊山].
	Naraku revived them as zombies [亡霊] and gave Bankotsu the Sacred Jewel fragments in exchange that they kill anyone following him. And they could keep the Sacred Jewel fragments after that.

Though cruel mercenaries, there are moments where the Shichintai show their loyalty and camaraderie.
	Here, Jakotsu, Renkotsu and Ginkotsu went to collect Suikotsu. Though irritated by Suikotsu's split personality, Jakotsu nonetheless helped him to escape from the clutches of Inuyasha.
	Ginkotsu and Renkotsu are a tight pair, often looking out for each other. Another tight pair is Jakotsu and Bankotsu. Jakotsu displays unquestionable loyalty to Bankotsu.
	When Bankotsu realized the traitor Renkotsu killed Jakotsu for his Sacred Jewel, his wrath was understandable. He avenged Jakotsu's death by killing Renkotsu, before heading off the avenge the Shichinintai.

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OTHERS:
The entire Shichinintai story arc may have been set at a real location. {Shichinintai-Chaos} pointed out that Ushitora may have based on the area around the sacred mountain of Nantai-san (also known as Kurokiyama and Futaarasan). Around the 8th century, a holy man called Shodo-Shounin-sama built a shrine there. Lake Chuzenji in the area also bears an uncanny resemble to Hijiri Island. Do read The "Real" Ushitora? at {Shichinitai-Chaos}, as it lists out the similarities between the two locations and even contains photos.

For a good site with articles on the Shichinintai, go to Shichinin-tai Chaos. The fanlisting can be found at Legendary.