The Upper Seal is a rare drop-based item introduced with the Sailor Piece Moon Update. It cannot be purchased, crafted, or traded for through any NPC — the only way to get one is by defeating enemies scattered across the game’s islands. Every mob in the game has a chance to drop it, but the odds are extremely low, making it one of the most tedious items to farm in Sailor Piece right now.
Quick answer: Defeat high-level mobs on Shinjuku, Lawless Island, or Ninja Island repeatedly. These endgame enemies offer the best Upper Seal drop rates, though the chance per kill is still lower than a Passive Shard drop.
Where Upper Seals Drop
Upper Seals can technically drop from any enemy on any island. In practice, though, farming low-level mobs on Starter Island or Jungle Island is a waste of time. The drop rate scales with enemy difficulty, so stronger mobs on late-game islands give you meaningfully better odds.
The three islands worth farming are:
| Island | Why It’s Good |
|---|---|
| Shinjuku | High-level mobs with dense spawn points |
| Lawless Island | Endgame enemies; also home to the Atomic boss summon |
| Ninja Island | Large mob count and high enemy levels; Madara auto-spawns here every 5 minutes |
Bosses across Sailor Piece also have better drop rates than regular mobs, but they take significantly longer to kill due to massive health pools. Because regular endgame mobs are far more numerous and die faster, grinding them is the more efficient path for pure Upper Seal farming.
Tips for Faster Upper Seal Farming
Since the drop chance is so low, small optimizations compound over hundreds of kills. The goal is to kill mobs as fast as possible while stacking every luck modifier you can.
Every Upper Seal Use in Sailor Piece
Upper Seals feed into three distinct unlocks, all tied to the Moon Slayer content path. You will need a total of 111 Upper Seals if you want to summon the Moon Slayer boss once and fully unlock the fighting style plus its F move.
| Use | Upper Seals Required | Other Requirements |
|---|---|---|
| Summon Moon Slayer boss at Boss Island | 1 | 700,000 Money, 700 Gems |
| Unlock Moon Slayer Fighting Style | 25 | Six-Eyed Demon title, 37,500 Gems, 1× Moon Crest, 4× Crescent Shard, 9× Lunar Essence, 16× Demon Remnant |
| Unlock Moon Slayer F Move | 85 | Upper clan, Moon Slayer fighting style already learned, 2× Moon Crest, 10× Crescent Shard |
The Moon Slayer boss is the hardest summonable boss in Sailor Piece as of the Moon Update. Defeating it drops the Six-Eyed Demon title, which grants +85% DMG and is itself a prerequisite for learning the Moon Slayer fighting style. So the progression chain looks like this: farm Upper Seals → summon and defeat Moon Slayer → earn the title → submit 25 more Upper Seals (plus other materials) to learn the style → farm 85 more Upper Seals to unlock the F move.
Moon Slayer Progression Chain at a Glance
Because the requirements stack across multiple steps, planning ahead saves time. Here’s the full sequence you need to follow:
Upper Seals represent one of the longest grinds in Sailor Piece, but the payoff — the Moon Slayer fighting style and its devastating F move — sits at the top of the game’s late-game power curve. Focus your farming sessions on Shinjuku, Lawless Island, or Ninja Island, stack every luck buff you can, and take advantage of weekend 2x Luck events whenever they’re active.
