To unlock dungeons in Sailor Piece you need three things: level 5,000, six hidden Ancient Pieces scattered across Sea 1, and 25 boss kills. After that you still spend a Dungeon Key every time you open a portal. This guia puts the whole chain in order, explains the three dungeons you can open once the quest is done, and shows what the Dungeon Merchant sells for the Dungeon Tokens you earn.
A quick honesty note. We did not play-test any of this. Everything below comes from the Sailor Piece Fandom wiki, mainly the Dungeon, Dungeon Master, Dungeon Merchant, Dungeon Island and Rune Dungeon pages, plus the Items and Boss Island pages for key drops. The Dungeon page was last edited on junho 12, 2026 and the Dungeon Master page on maio 29, 2026. Where the wiki leaves a field empty or contradicts itself, we say so.
Dungeon requirements at a glance
| Requirement | What the wiki says |
|---|---|
| Island | Dungeon Island, Sea 1 (after Boss Island, before Shinjuku Island) |
| Level | 5,000 |
| Quest 1 | "Discover Dungeon": find 6 Ancient Pieces across Sea 1, in order |
| Quest 2 | "Prove Your Strength": defeat 25 bosses (any) |
| NPC | Dungeon Master, at the center of Dungeon Island, next to the portal |
| To start and replay | Dungeon Key (the wiki gives no quantity) |
| Reward currency | Dungeon Tokens, spent at the Dungeon Merchant |
You can read up on the island on our own pages: Dungeon Island, the NPC list for the Dungeon Master, and the list of every dungeon and raid.
Step 1: reach level 5,000 and get to Dungeon Island
Level 5,000 is the gate, and the Dungeon Master will not start the quest before it. In island order, Dungeon Island sits right after Boss Island, and the Islands page lists a suggested level of 5,000 for it. It is a small island. The wiki says its core is the Dungeon Portal, and the Dungeon Master is the only NPC who can spawn that portal.
Four NPCs live there: the Dungeon Master, the Dungeon Merchant, the Shadow Seller and the Shadow Monarch Seller. Two of those sell swords, so the island pays off even if you only came for the quest. We cover the sword requirements in our Shadow sword guia.
Step 2: find the six Ancient Pieces
This is the part people get stuck on, and the wiki's wording is short. The Dungeon Master's first quest, "Discover Dungeon", tells you to find six Ancient Pieces across the islands, and the page adds "In Order". (The Dungeon page calls the same quest "Dungeon Discovery", and says all six pieces are in Sea 1.) The wiki shows one screenshot per piece and gives a one-line location for each.
| Piece | Island | Where, according to the wiki |
|---|---|---|
| 1 | Starter Island | On the island (screenshot on the wiki) |
| 2 | Jungle Island | At the edge of the island |
| 3 | Desert Island | At the edge of the island |
| 4 | Snow Island | Behind the tree |
| 5 | Shibuya Station | Between the tallest buildings |
| 6 | Hollow Island | On top of the roof |
Look at the route. It walks you through six Sea 1 islands, and by the Islands page's suggested levels they run from low to high: Starter Island (level 1 to 249) up to Hollow Island (5,000 to 6,250). At level 5,000 you have outleveled the first five, so for those the trip is mostly travel time. Hollow Island is the one whose suggested range still starts at 5,000, so that last stop is the only one where you may meet resistance. Our pages for Starter Island, Snow Island, Shibuya Station and Hollow Island help you find your way around.
Two things the wiki does not tell you. First, whether a piece is collected by walking into it or by pressing a prompt. Second, what happens if you pick them up out of order. Because the page says "In Order", do them in order and you avoid finding out. The wiki also links a video guia titled "How To Unlock & Do Dungeons in Sailor Piece", which shows all six locations if the screenshots are not enough.
Step 3: defeat 25 bosses
The second quest, "Prove Your Strength", is a kill counter: defeat 25 bosses, any bosses. The wiki does not say whether Boss Rush or dungeon bosses count toward it, so the safe plan is to use ordinary world bosses and the summonable bosses on Boss Island.
Summoning on Boss Island costs items. The Boss Island page lists 1 Boss Key plus 100,000 coins and 175 gems for the Excalibur boss, 3 Boss Keys (and coins and gems) for Qin Shi and 5 for the Soul Reaper. The later bosses use other materials instead, for example a Divine Grail for King of Heroes. The Boss Key drops from any NPC quest or chest, according to the Items page. Cheap bosses first, then.
Do the 25 kills while you farm Dungeon Keys, because the same bosses drop them (next section). The quest and your first dungeon runs then cost the same time.
Where to get Dungeon Keys
A Dungeon Key opens a dungeon, and the Dungeon page says starting a dungeon and replaying both require it (it gives no quantity). The Items page says it drops from most NPCs at around 40 to 60 percent. The Boss Island page also lists it as a boss drop:
| Boss | Dungeon Key drop chance |
|---|---|
| Excalibur | 10% |
| Qin Shi | 15% |
| Soul Reaper | 20% |
| King of Heroes | 30% |
| Blessed Maiden | 30% |
| Corrupted Knight | 30% |
| Moon Slayer | 30% |
On the numbers alone, the later summon bosses drop keys most often, though they also cost more to summon. The wiki gives Ice Queen no Dungeon Key chance at all. With a 40 to 60 percent chance from ordinary NPCs, our guess is that keys will not be scarce while you grind levels, but the wiki does not say how many a run uses. The same page shows that every boss it lists drops a Boss Ticket at 100%, which matters for a different goal.
The three dungeons
Once both quests are done, the Dungeon Master spawns portals. The Dungeon page names three dungeon types, and all three have Easy, Medium, Hard and Extreme difficulty and 15 waves.
| Dungeon | Enemies | Boss waves | Main use |
|---|---|---|---|
| Cid Dungeon (also called the Shadow Dungeon) | Not listed | Cid boss on waves 5, 10 and 15 | Ascensions, Dungeon Tokens, the Shadow sword, the Eminence in Shadow title |
| Rune Dungeon | Raider, Commander, Knight, Black Knight | None listed | Obtaining and leveling Runes |
| Double Dungeon | Knight, Black Knight, Strong Knight, Commander | Shadow Monarch boss on waves 5, 10 and 15 | The Shadow Monarch sword and the King of Shadows title |
Cid Dungeon
The Cid boss drops the crafting items for the Shadow sword: Atomic Cores, Shadow Essence, Void Seeds and Umbral Capsules. The Items page gives drop ranges of 12.5 to 35% for Umbral Capsule, 4.5 to 15% for Void Seed and 2 to 4.5% for Shadow Essence. The Atomic Core chance is still "TBA". The full requirement list is in our Shadow sword guia, and the boss has its own Shadow boss page.
Rune Dungeon
Enemies here drop Runes, with two exceptions: the wiki says Primordial and Radiant runes do not drop in this dungeon. The Rune Dungeon page lists these chances:
| Rune | Drop chance |
|---|---|
| Suppression | 1.5% |
| Guardian | 1.25% |
| Destruction | 1% |
| Frost Rune | 0.75% |
| Blood Rune | 0.5% |
| Inferno Rune | 0.25% |
| Wrath Rune | 0.1% |
| Fortune Rune | 0.09% |
| Havoc Rune | 0.03% |
The page adds one rule worth remembering: the harder the dungeon, the better the rune that drops. It does not publish separate numbers per difficulty, so treat the table as the general picture.
Double Dungeon
The Double Dungeon is the Shadow Monarch route. It drops the Monarch Core, Monarch Essence, Kamish Dagger, Monarch Armor and Shadow Crystal. The wiki also has a separate "Shadow Monarch Dungeon" page, which says that dungeon is used to get the materials for the Shadow Monarch Seller on top of Dungeon Island. These look like two names for the same content, but the wiki does not say so outright.
Dungeon Tokens and the Dungeon Merchant
Finishing any dungeon pays Dungeon Tokens. The Dungeon Merchant on Dungeon Island sells the following with no purchase limit, according to the wiki:
| Item | Price in Dungeon Tokens |
|---|---|
| Atomic Core | 65 |
| Shadow Essence | 25 |
| Void Seed | 15 |
| Umbral Capsule | 5 |
| Shadow Cloak | 50 |
| Boss Key | 1 |
| Common Chest | 1 |
| Rare Chest | 2 |
| Epic Chest | 4 |
| Legendary Chest | 8 |
| Mythical Chest | 20 |
Here is the useful bit of arithmetic. The Shadow sword wants 1 Atomic Core, 4 Shadow Essence, 8 Void Seeds and 20 Umbral Capsules. At merchant prices that is 65 + 100 + 120 + 100, so 385 Dungeon Tokens buys the full material set with no luck involved. That covers the materials only: the same Shadow (Sword) page also lists the Shadowborn race, 10,000,000 money and 15,000 gems as requirements. The wiki does not say how many tokens a run pays, so we cannot turn 385 into a number of runs. It does make the Merchant the right place to spend your first tokens if the Shadow sword is your goal.
Boss Keys at 1 token each loop back into Step 3: tokens can pay for the summons that drop more Dungeon Keys.
Which dungeon should you run first?
Our pick is the Cid Dungeon. It feeds the token economy, it gives you the Shadow sword materials, and the wiki lists Ascensions among its uses. Run the Rune Dungeon when you are hunting a specific rune, and the Double Dungeon when the Shadow Monarch requirements are in sight.
One naming trap. The Shadow Master quest line on the wiki says "Beat Easy Shadow Dungeon 10 Times", then Medium, then Hard, and the Cid Dungeon page says Cid is "otherwise known as Shadow Dungeon". So that quest line most likely means the Cid Dungeon, though the Shadow Master page never says so. It is the F-move quest for the Shadow sword, not a requirement for opening dungeons.
What the wiki does not say
- No wave-by-wave enemy list or boss health numbers for any dungeon.
- No number of Dungeon Tokens per run or per difficulty.
- No separate drop numbers per dungeon difficulty, apart from the rule that harder is better for runes.
- Whether the 25 boss kills include Boss Rush or dungeon bosses.
If you test one of these yourself, treat our answer as unconfirmed until the wiki lists it.
Quick checklist
- Level 5,000 reached
- Six Ancient Pieces collected in order, from Starter Island to Hollow Island
- 25 bosses defeated
- Dungeon Keys in your bag for your runs
- The Dungeon Master has spawned the portal on Dungeon Island
Frequently asked questions
What level do you need to unlock dungeons in Sailor Piece?
Level 5,000. The Dungeon Master will not start the quest before it.
Where are the six dungeon pieces?
Starter Island, the edge of Jungle Island, the edge of Desert Island, behind the tree on Snow Island, between the tallest buildings at Shibuya Station and on a roof at Hollow Island, collected in that order.
How many bosses do you need to defeat?
25 bosses. The wiki says any boss counts, but it does not say whether Boss Rush or dungeon bosses are included.
How do you get a Dungeon Key?
It drops from most NPCs at around 40 to 60 percent and from bosses such as Excalibur (10%) and Moon Slayer (30%).
What are Dungeon Tokens for?
You spend them at the Dungeon Merchant on Dungeon Island, on Atomic Core, Shadow Essence, Void Seed, Umbral Capsule, Shadow Cloak, Boss Keys and chests.
Which dungeon gives the Shadow sword materials?
The Cid Dungeon. Its boss drops Atomic Cores, Shadow Essence, Void Seeds and Umbral Capsules.
Sources
- Sailor Piece Fandom wiki: Dungeon, Dungeon Master, Dungeon Merchant, Dungeon Island, Rune Dungeon, Cid Dungeon, Boss Island, Items, Islands and Shadow Master and Shadow (Sword)).
- Our own entity pages for the islands, items and bosses linked above, which are built from the same wiki.