The Charm of Inari's Might is a minor Melee charm in Ghost of Tsushima. Gives a small boost to your health and your sword damage, and it grows stronger as you honor more Inari Shrines. You get it by honoring 20 Inari Shrines.
Follow foxes from fox dens to Inari Shrines and honor them. Once your minor charm slots are all open, further shrines build toward this charm. There are 49 shrines across Izuhara, Toyotama and Kamiagata.
Paired with the Sakai Clan Armor, the health and melee boosts stack into a massive bonus.