Hogyoku Fragments in Sailor Piece serve two distinct purposes. They are Mythical-rarity items that can drop from the Aizen boss fight on Hueco Mundo, and they are also collectible puzzle pieces scattered around the world as part of the Hogyoku Quest — the only way to reach Soul Society Island.
Quick answer: To complete the Hogyoku Quest and unlock Soul Society, talk to the Hogyoku Quest NPC on Hueco Mundo Island, then interact with six Hogyoku Fragments hidden on Snow Island, Shibuya Station, Hueco Mundo, Shinjuku Island, Slime Island, and Judgement Island — in that exact order — before returning to the NPC to open a 120-second portal.
Starting the Hogyoku Quest
Head to Hueco Mundo Island and look for the Hogyoku Quest NPC on the far left side of the island, near the Aizen Mastery NPC. Speaking with this NPC kicks off the quest and tasks you with finding all six Hogyoku Fragments spread across the map. The fragments must be collected in a fixed sequence — picking them up out of order won't count.
All Six Hogyoku Fragment Locations (In Order)
| # | Island | Exact Spot |
|---|---|---|
| 1 | Snow Island | Climb the hills next to the small pond on the right side of the island. The fragment sits on a branch of a nearby tree. |
| 2 | Shibuya Station | On top of the building directly behind where the Yuji world boss spawns. |
| 3 | Hueco Mundo | On a brown pipe right next to the Aizen world boss spawn point. |
| 4 | Shinjuku Island | Jump onto the building furthest to the right (the one with the Strongest in History trainer on top), then leap to the small protruding platform on the building across from it. |
| 5 | Slime Island | Run along the left edge of the island until you pass the Rimuru Mastery trainer, then turn back and jump onto the branch of the tree in the middle of the area. |
| 6 | Judgement Island | On a ledge of an iceberg very close to the spawn point. Run along the right edge of the island to reach it. |
Fragment #1 — Snow Island
Teleport to Snow Island and head toward the right side where a small pond sits at the base of some hills. Climb up the hillside and look for a tree with a branch extending outward. The first Hogyoku Fragment rests on that branch. It can be easy to miss if you're scanning at ground level, so keep your camera angled upward as you approach.
Fragment #2 — Shibuya Station
Once on Shibuya Station island, locate the Yuji world boss spawn. The fragment is perched on the rooftop of the building immediately behind that spawn point. You'll need to jump or use movement abilities to get on top of the structure.
Fragment #3 — Hueco Mundo
This one is conveniently close to where the quest begins. From the Aizen world boss spawn in the center of Hueco Mundo, look for a brown pipe nearby. The third fragment is sitting right on it. If Aizen is currently active, you can still grab the fragment without engaging the boss.
Fragment #4 — Shinjuku Island
Teleport to Shinjuku Island and find the building furthest to the right — the Strongest in History trainer stands on its roof. Climb to the top of that building first, then look across to the adjacent structure. A small platform juts out from its side. Jump over to that platform to collect the fourth fragment.
Fragment #5 — Slime Island
On Slime Island, hug the left edge and run forward until you spot the Rimuru Mastery trainer. Once you've passed the trainer, turn around and look for a tree in the center of the area. The fragment is on one of its branches, so you'll need to jump up to grab it.
Fragment #6 — Judgement Island
The final fragment is on Judgement Island, and it's one of the easier ones to reach. From the spawn point, run along the right edge of the island. You'll quickly come across an iceberg with a visible ledge. The sixth Hogyoku Fragment sits on that ledge.
Opening the Soul Society Portal
After collecting all six fragments, return to Hueco Mundo Island and speak with the Hogyoku Quest NPC again. A portal will appear right next to the NPC. You have exactly 120 seconds to step through it before it closes. Walking into the portal teleports you to Soul Society Island.
The good news is that this is a one-time gate. After your first visit to Soul Society, the island becomes permanently available through the standard Teleport Portals found on every island in Sailor Piece. You won't need to repeat the quest or talk to the NPC again.
Hogyoku Fragment as an Aizen Boss Drop
Separate from the quest collectibles, the Hogyoku Fragment also exists as a Mythical item that drops from the Aizen open-world boss encounter on Hueco Mundo. Aizen spawns in the center of the island and is available to fight whenever the respawn timer isn't active. If another player has already defeated Aizen, you'll see the boss's name floating in the air with a countdown until the next spawn.
The drop rate for the Hogyoku Fragment from Aizen is 3.6%. Dealing more damage to the boss increases your odds of receiving better rewards overall. Equipping Runes that boost your Luck stat can also help improve the chance of a drop, though you should still expect to farm this fight multiple times before one appears.
Between the quest fragments and the boss drop, Hogyoku Fragments touch two very different parts of Sailor Piece's progression. The quest version unlocks an entire new island and only needs to be done once, while the Aizen drop is a repeatable Mythical item tied to endgame farming. Knock out the quest first to open up Soul Society, then circle back to grind Aizen whenever you're ready for the RNG.