The Charm of Precision is a minor Ranged charm in Ghost of Tsushima. Your arrows deal a moderate amount of extra damage. You get it by finishing The Past Never Passes, Dreams of Conquest or Laid to Rest.
Any of these tales gives it as a reward: The Past Never Passes, Dreams of Conquest, Laid to Rest.
Midnight Shark
Midnight Shark is a dye for the Half Bow. It is a reward for completing "Laid to Rest" (Ishikawa's tales, part 9 of 9). Like every dye it only changes colours.
Shattered Mask of Tomoe
Shattered Mask of Tomoe is a mask you get by finishing "Laid to Rest", from Ishikawa's tales, part 9 of 9. It is a story reward, so playing the tale is the only way to add it.
Image: Sucker Punch Productions / PlayStationBamboo Strikes
Bamboo Strikes are button-timing challenges where Jin slices a row of bamboo poles. There are 20 in all, 16 on Tsushima and 4 on Iki, and completing them raises your maximum Resolve.
Charm of Advantage
The Charm of Advantage is a minor Melee charm in Ghost of Tsushima. Ghost weapons deal 20% more damage. You get it by finishing The Cost of Iron or Nattou and the Sake Seller.