Sekiro-shadows-die-twice-v1-02 -

In version 1.02, many players were just starting out and looking for the "proper" tools to beat early bosses like the Chained Ogre:

Sold by the Dungeon Memorial Mob near the Abandoned Dungeon Entrance for 5,000 Sen. 2. Key Prosthetic "Pieces" (Early Game) sekiro-shadows-die-twice-v1-02

If you're looking to increase your health ("properly" buffing your character), you need (found after mini-bosses) or Gourd Seeds (to increase your healing flask uses). In version 1

Sold by the Pot Noble Harunaga in Hirata Estate for 7 Treasure Carp Scales. In version 1.02