The PCs met Shiroi during the course of their investigation into the madness of Hiruma Makasu. He was their link back to Hida Yakamo, and was responsible for bringing Hida Kisada to relieve Shiro Kuni. Shiroi and the Great Bear held the gate while the PCs removed Makasu from command.
Shiroi is available as an ally to Crab characters. He has an influence of 1 and can have any rank of devotion.