The Blue Key is one of three colored keys you need during Chapter 1 of Beast of Reincarnation, all of which unlock the sealed door leading to the Nushi’s Lair in Subcity 03. You pick it up during the “Toward the Nushi’s Lair” main quest, right after the Red Key marks the remaining locations on your map.
Quick answer: Take the Red Key from the gatekeeper first, then follow the Blue Key marker to the Central Riverbank in the Ogouchi Buffer Zone. Use Emma’s Hair to cross the gap up to the lookout camp, then interact with the purple glowing object to collect the Blue Key.
What you need before going for the Blue Key
Two things gate this pickup. First, the Red Key has to be in your inventory, since talking to the gatekeeper near the sealed door is what places the Blue and Yellow Key markers on your map. Second, you must have unlocked Emma’s Hair traversal ability, because the route to the Blue Key crosses a large gap you cannot clear without it.
| Detail | Info |
|---|---|
| Item | Blue Key |
| Quest | Toward the Nushi’s Lair (Chapter 1) |
| Area | Central Riverbank, Ogouchi Buffer Zone |
| Requirement | Red Key obtained, Emma’s Hair unlocked |
| Combat | None required |
If you have already picked up the Red Key from the gatekeeper and have not fast traveled away, the Blue Key marker is the closest of the two remaining objectives. That proximity, plus the lack of any major fight, makes it the sensible second key to collect.
Blue Key location and route in the Ogouchi Buffer Zone
The key sits in the open at a lookout camp on the cliffside above the Central Riverbank, near a broken golem by the Subcity 03 watchtower. The path is short once you know where to climb.
You will know it worked when the objective updates automatically and the key appears in your inventory. The Blue Key marker clears from your map at the same time.
What the Blue Key unlocks
The Blue Key has two uses. Its main job is opening the large sealed door in Subcity 03, but only after you also hold the Red and Yellow Keys. On its own it does not progress the story.
Away from the main quest, the Blue Key also opens a storage door in a cavern near the starting area, which gives you access to a strongbox. That detour is optional and does not affect Chapter 1 progress.
| Key | How to get it |
|---|---|
| Red Key | Given by the gatekeeper near the sealed door in Subcity 03 |
| Blue Key | On the ground at the Central Riverbank lookout camp |
| Yellow Key | Defeat the Grizzly Malefact for the Tailwater Key, then open the locked room |
With the Blue Key secured, the Yellow Key is the last piece. It cannot be grabbed directly. You need to reach the cave past the rice fields, defeat the elite Grizzly Malefact to earn the Tailwater Key, then use that key to open the room holding the Yellow Key. Once all three are in your inventory, return to the sealed door where you received the Red Key to continue Chapter 1.
