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).
Since the "v1.02" tag is often associated with early release versions or specific community-repack discussions, here are the most likely "pieces" you might be looking for: 1. The Dancing Dragon Mask Pieces sekiro-shadows-die-twice-v1-02
Sold by the Pot Noble Harunaga in Hirata Estate for 7 Treasure Carp Scales. If you're looking to increase your health ("properly"
Are you trying to find a specific item to progress past a certain boss? Sekiro: Shadows Die Twice - Walkthrough Part 1: Shinobi Are you trying to find a specific item
Sold by the Dungeon Memorial Mob near the Abandoned Dungeon Entrance for 5,000 Sen. 2. Key Prosthetic "Pieces" (Early Game)
If you are looking for a "piece" to complete a larger set, it's likely one of the three fragments of the Dancing Dragon Mask :