Vitality and posture can be upgraded by finding
Prayer Beads. You can redeem four Prayer Beads at any Sculptor's Idol to receive a Prayer Necklace which result in a permanent increase to vitality and posture. There are 40 Prayer Beads in the game and you must collect them all on a single save file (ultimately receiving the 10 Prayer Necklaces) for this achievement.
29 Prayer Beads are dropped by mini bosses (most of which are optional battles), 6 are found in chests, 4 are found as items in specific locations, and one is sold by a vendor.
Some of the required mini bosses are only available during specific parts of a playthrough, some are only available if you progress towards the standard ending (choose
Break the Iron Code, stay loyal to Kuro when you encounter Owl at the top of Ashina Castle), and some are only available if you progress towards the Purification ending. Further info can be found on the Sekiro Wiki:
https://sekiroshadowsdietwice.wiki.fextralife.com/Prayer+Bea...Note that each of the 40 Prayer Beads is unique and while you can work on collecting any that you might have missed during subsequent playthroughs, you must acquire all 40 of them as enemies who drop Prayer Beads only drop them the first time you kill them and any found in static locations throughout the world will be a different item the second time you find them.
This is a general order you can find them in as you play through the game.
1: dropped by General Naomori Kawarada just past the Outskirts Wall - Gate Path idol
2: dropped by the Chained Ogre near the Outskirts Wall - Stairway idol
3: dropped by General Tenzen Yamauchi just past the Chained Ogre
4: dropped by Shinobi Hunter Enshin of Misen in Hirata Estate
5: found in a chest
at the top of a building accessible after defeating Gyoubu Masataka Oniwa6: dropped by the Blazing Bull near the Ashina Outskirts – Ashina Castle Gate idol
7: dropped by Juzou the Drunkard in Hirata Estates
8: found in a chest
behind a secret wall just after Juzou the Drunkard9: dropped by Seven Achina Spears – Shikibu Toshikatsu Yamauchi in Ashina Reservoir
10: dropped by Lone Shadow Longswordman in Ashina Reservoir
11: purchased for 1400 Sen from the Memorial Mob by the Abandoned Dungeon Entrance idol
12: dropped by General Kuranosuke Matsumoto in Ashina Castle
13: found as an item
on the ground in an area near the Under-Shrine Valley idol14: found in a chest
behind a secret wall near the Upper Tower - Antechamber idol15: dropped by Ashina Elite – Jinsuke Saze near the Upper Tower - Ashina Dojo idol
16: dropped by Armored Warrior after the Senpou Temple – Shugendo idol
17: dropped by Long-arm Centipede Sen’un after Senpou Temple - Temple Grounds idol
18: dropped by Snake Eyes Shirafuji near the Sunken Valley Idol
19: dropped by Long-arm Centipede Giraffe Near the Sunken Valley - Gun Fort idol
20: found as an item
in an area through the hole in the floor in Long-arm Centipede Giraffe's room21: dropped by Snake Eyes Shirahagi near the Poison Pool idol in Ashina Depths
22: found as an item
on top of a statue near the Poison Pool idol in Ashina Depths
23: dropped by Tokujiro the Glutton in the Hidden Forest in Ashina Depths
24: dropped by O'rin of the Water near the Water Mill idol in Ashina Depths
25: found as an item
in the top floor of a house in Mibu Village26: found as an item
in the water near the Senpou Temple – Temple Grounds idol27: found in a chest
in the lake by the Water Mill idol in Ashina Depths28: droppped by Lone Shadow Masanaga the Spear-Bearer at Ashina Castle – Great Serpent Shrine
29: dropped by the Chained Ogre below the Ashina Castle – Upper Tower Antechamber idol
30: dropped by Lone Shadow Vilehand near the Ashina Castle – Upper Tower Dojo idol
31 and 32: dropped by the Undying Guardian Ape near the Poison Pool idol in Ashina Depths
IMPORTANT: The next two Prayer Beads are only obtainable if you follow the steps to reach the Purification ending, during which you return to Hirata Estate on a different timeline.
33: dropped by Lone Shadow, Masanaga the Spear-Bearer in Hirata Estate
34: dropped by Juzou the Drunkard in Hirata Estate
35: dropped by Sakura Bull of the Palace in Fountainhead Palace
36: dropped by Okami Leader Shizu in Fountainhead Palace
37: found in a chest in the large lake in Fountainhead Palace
The following three mini bosses are only available after defeating the Divine Dragon.
38: dropped by Seven Spears Ashina – Shume Masaji Oniwa in Ashina Reservoir
39: dropped by Ujinari Mizou in Isshin's hidden dojo
found near the Upper Tower Dojo idol40: dropped by Shigekichi of the Red Guard near the Outskirts Wall - Stairway idol
After redeeming the final four Prayer Beads and obtaining the Final Prayer Necklace, the trophy will pop.