The time is Sengoku. 
 
Japan is fractured into many independent nations entangled in ceaseless war. At the center lies Ashina, a land of sacred earth and ancient mystery. Two decades after Sword Saint Isshin Ashina reclaimed the region in a brutal coup, a new threat emerges from within: The Interior Ministry. Desperate to protect his homeland, Isshin's grandson Genichiro turns to forbidden powers. The only hope lies in a kidnapped boy — the Divine Heir — and his silent protector: a loyal shinobi known only as Sekiro. 
 
This is the story of a lord and his retainer — and their quest to restore balance to a nation on the edge. 
 
(Source: Crunchyroll)

[Wiki (jp)](https://ja.wikipedia.org/wiki/土師孝也)

Fukrou