The Azure Heart is a Mythical-rarity material in Sailor Piece that sits at the very bottom of one boss's loot table. It cannot be found in chests, purchased from shops, or obtained from any other enemy in the game. If you need one — and late-game progression guarantees you will — there is exactly one path to getting it.
Quick answer: Defeat the Yamato boss on Judgment Island. The Azure Heart has roughly a 0.5–0.6% chance of dropping per kill. There is no alternative source.
Yamato Boss Location on Judgment Island
Yamato is an open-world boss stationed on Judgment Island. You can reach the island by using the teleporter available on any island in the game — no special key, quest item, or fee is required to access it. Once you arrive, head toward the mountainous area at the far end of the island. Yamato spawns there automatically and remains in the area until a player defeats it.
Because Yamato is a world boss, other players on the same server can kill it before you arrive. If that happens, a respawn timer appears at the boss's spawn point. Yamato respawns every six minutes and thirty seconds after being defeated, so the wait is relatively short. A common farming tactic is to server-hop — leave and rejoin a fresh server — to skip the cooldown entirely and fight the boss again immediately.
Azure Heart Drop Rate
The exact drop percentage varies slightly depending on where you look, but the Azure Heart consistently falls in the range of approximately 0.5% to 0.59%. That translates to roughly one drop per 170–200 kills on average, though randomness means your actual experience could be far better or far worse. Yamato has around 850 million HP, so each fight is a significant time investment unless your build can burst through that health pool quickly.
Sailor Piece does feature a pity system that kicks in around 25 boss kills, which can force a Mythical-tier drop. However, the pity system does not guarantee the Azure Heart specifically — it could hand you a different Mythical item from Yamato's loot table instead.
How to Improve Your Odds
While you cannot manipulate the Azure Heart's specific drop chance on Yamato, raising your overall luck stat gives you a better shot at rare drops across the board. Several systems in Sailor Piece contribute to luck.
| Luck Source | How It Helps |
|---|---|
| Titles | Equip luck-boosting titles like Celestial Favor or Destiny Marked |
| Skill Tree | Allocate stat points toward luck nodes |
| Runes | Equip runes that provide luck bonuses |
| Clans | Some clans grant passive luck increases |
| Races | Certain races offer higher base luck |
| Gamepasses | Optional premium luck multipliers |
| Weekend Events | 2x or 3x Luck events rotate periodically |
Beyond luck, you also need enough raw damage to take Yamato down efficiently. Optimizing your sword choice, fighting style, and Spec Passives will shorten each kill and let you squeeze more attempts into every farming session.
What the Azure Heart Is Used For
The Azure Heart serves two distinct purposes in Sailor Piece's endgame, and you'll need a total of three if you want to complete both.
Unlocking the Yamato Sword
An NPC located on top of the mountains on Judgment Island, to the left of the portal, offers the Yamato sword in exchange for a specific set of materials and conditions. The full requirements are listed below.
| Requirement | Details |
|---|---|
| Azure Heart | 1x |
| Silent Storm | 3x |
| Yamato Essence | 7x |
| Frozen Will | 14x |
| Gems | 30,000 |
| Title | Blade Sovereign (must be equipped) |
| Race | Swordblessed (must be active) |
Silent Storm, Yamato Essence, Frozen Will, and the Blade Sovereign title all drop from the Yamato boss fight itself, so you'll naturally accumulate them while farming for the Azure Heart. The Swordblessed Race is a separate grind — it's a Mythical race obtained through Race Rerolls, which you earn by defeating any boss or opening chests. Yamato guarantees a Race Reroll on every kill, making the boss fight doubly worthwhile.
Ascension Level 9
The Moon Update introduced Ascension levels 9 and 10. Reaching Ascension 9 requires submitting 2x Azure Hearts along with 2x Evolution Fragments and completing several combat milestones. The full Ascension 9 checklist includes reaching level 11,500, killing 1,500 NPCs, killing 700 bosses, dealing 1 trillion damage, using 1,500 abilities, and clearing 15 Medium or higher Boss Rushes. Completing it grants permanent buffs of +10% Gems, +10% Money, and +5% Luck.
Combined with the one needed for the Yamato sword, that brings the total Azure Hearts you'll eventually want to three.
Other Yamato Boss Drops
Every Yamato kill has a chance to reward several items beyond the Azure Heart. Knowing what else is in the loot table helps set expectations for your farming runs.
| Drop | Notes |
|---|---|
| Frozen Will | Common drop; 14 needed for the Yamato sword |
| Yamato Essence | Moderate drop; 7 needed for the Yamato sword |
| Silent Storm | Less common; 3 needed for the Yamato sword |
| Blade Sovereign title | Chance to unlock; required to equip when buying the sword |
| Race Reroll | Guaranteed every kill |
| Azure Heart | ~0.5–0.59% chance; Mythical rarity |
The guaranteed Race Reroll is a nice consolation on runs where the Azure Heart doesn't appear, since it feeds directly into your attempts to roll the Swordblessed Race.
Farming the Azure Heart is one of the longest grinds in Sailor Piece, but there's no shortcut around it. Stack as much luck as your build allows, optimize your damage to speed up each Yamato kill, and server-hop to avoid downtime between respawns. With roughly 170–200 kills needed on average, patience is the real endgame requirement.