The Whetstone is a usable item in Nioh 3 that instantly raises the familiarity of your currently equipped weapon by 150 points. That might not sound like much in isolation, but stacking several of them lets you skip hours of grinding and jump straight to unlocking crucible skills on a brand-new weapon. The problem most players run into is simple: whetstones are extremely hard to come by in the early game, and the game never really explains where they come from.
Quick answer: Offer unwanted gear at any shrine during a mission. Whetstones drop as an occasional RNG reward from shrine offerings — this is the most reliable early-game source.
What the Whetstone actually does
Using a Whetstone applies a flat 150-point boost to the familiarity meter of whichever weapon you have equipped at that moment. Familiarity in Nioh 3 is tracked per individual weapon, not per weapon type, so swapping to a freshly looted sword resets you to zero even if you maxed out a different sword earlier. Higher familiarity unlocks weapon skills, passive bonuses, and crucible abilities — the most important being the crucible skill that typically gates at 900 familiarity.
You can carry up to 99 Whetstones in your Item Box for use during missions, and store up to 9,999 in the Storehouse. Items sitting in the Storehouse are not accessible mid-mission, so you need to transfer them to your Item Box beforehand. Whetstones can be used from the items menu on the map screen, during missions, or from the interim — but they cannot be used inside the Dojo, since the Dojo blocks familiarity gain entirely.
How to get Whetstones early in Nioh 3
The single most consistent method during the opening regions is offering equipment at shrines. When you interact with a shrine during a mission, you can offer weapons, armor, and accessories you don't need. Along with Amrita, the shrine occasionally rewards you with Whetstones. The drop is RNG-based — there's no confirmed way to guarantee one every time — but offering higher-rarity gear (purple and above) appears to improve the odds. Since you'll be drowning in loot after a few missions, making a habit of offering everything you won't use is the easiest path to building up a small stockpile.
Outside of shrine offerings, early-game options are thin. Enemy drops exist but are extremely rare in the first couple of regions. Mission completion rewards sometimes include Whetstones, though this is inconsistent and tends to improve in later areas. Shops and NPC vendors that sell Whetstones don't become available until you've progressed further into the story.
The scarcity is deliberate. Nioh 3's crucible weapon system is designed to slow early progression and encourage you to learn your weapon through actual combat rather than bypassing the familiarity curve with consumables. Once you push past the opening regions, Whetstones start appearing much more frequently through drops, rewards, and vendor inventories.
Farming familiarity without Whetstones
If you're sitting at zero Whetstones and need to raise familiarity, the straightforward answer is to keep fighting with the weapon you want to level. Familiarity increases through landing hits and killing enemies — simply having a weapon equipped does nothing on its own. The gain is slow early on, but it compounds over time as long as you stick with the same weapon.
For faster results, target enemy-dense areas near shrines. Groups of weaker enemies generate more hits and kills per minute than a single tough yokai, and the nearby shrine lets you reset the area and repeat the loop. Clearing side paths and patrol routes rather than rushing objectives also helps, since every extra fight contributes to the meter.
If you're running two weapons and can't decide which to commit to, both equipped weapons gain familiarity as you fight, even if you favor one over the other. Swapping mid-mission spreads the gain across both, which is slower per weapon but more efficient overall when you're still experimenting with builds.
Late-game Whetstone use and stacking
Whetstones become far more powerful once you have a large supply. In the endgame and New Game Plus, you can use them to instantly boost a freshly acquired weapon all the way to 900 familiarity, unlocking its crucible skill without swinging it once. This is especially valuable when you pick up a high-level weapon with better stats but don't want to grind familiarity from scratch before it becomes fully functional in your build.
With 99 Whetstones in your Item Box — each granting 150 familiarity — you can apply up to 14,850 familiarity in a single sitting. That's more than enough to max out any weapon. The key is simply accumulating them over time through consistent shrine offerings and the broader loot sources that open up in later regions.
Whetstones are one of those items that feel invisible for the first several hours and then become a core part of weapon management once you understand the system. If you're early in Nioh 3 and haven't seen a single one, nothing is broken — keep offering gear at shrines, keep fighting with the weapon you want to level, and the supply will catch up to the demand as you progress.
