Shin Megami Tensei 3: Nocturne (SMT Nocturne)

How to Open Locked Door in Mantra HQ

Shin Megami Tensei III Nocturne - How to Open Locked Door in Mantra HQ.png

This is a guide to opening the Mantra HQ prison door in Ikebukuro for Shin Megami Tensei III HD Remaster (SMT Nocturne). Read on to learn how to open the door in Ikebukuro as well as the rewards inside!

How to Find the Locked Door

The Door is in the Mantra HQ Prison

The door can be found just after all the prisoner cells in the Mantra HQ Prison. The Prison itself is in the B1 level of the Mantra HQ Building.

Speak to the Incubus demon prisoner next to Isamu's cell, and he will direct you to the locked door.

Can only be Accessed After Beating Thor

Thor Boss Fight

The door can only be accessed after the Thor boss fight when you first arrive at the Mantra HQ.

After you beat the boss, players will be allowed to explore the Mantra HQ Building. Simply take the elevator or the stairs down to the basement to find the prison.

How to Beat Thor

How to Open the Locked Door

You need 24 Base Strength

Opening the Door

In order to open the locked door, players will need 24 points in the Strength Stat. This is base Strength which means that any bonuses from Magatamas will not be counted.

Players without 24 Base Strength will have to level-up and invest in the stat to open the door. For a tips on how to level-up quickly, visit our Best Leveling Areas page!

What Does Strength Do

Locked Door Rewards

Cache Cube with the Gaea Magatama

Gaea Magatama Reward

There will be a single Cache Cube behind the locked door. It will have the Gaea Magatama inside it. The Gaea Magatama is a good Physical Magatama which greatly resonates with the required stat to open the door. This is one of the best Magatamas to have for physical builds.

Gaea Magatama Stats

Shin Megami Tensei III: Nocturne Related Guides

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Tips and Tricks

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How to Heal and Revive Demons How to Recruit Demons
Fusion Calculator Guide How to Farm Lucky Tickets
Rag's Jewelry Shop Build Guide: Best Demi-fiend Stat Builds
How to Fuse Demons Mystical Chests Guide: List of Mystical Chests
What is the Kagutsuchi List of Evolving Demons
Best Leveling Areas How to Unlock the Compendium
Joining the Mantra: Gozu's Question List of Trophies and Achievements
How to Get Deathstones How to Return to the Amala Labyrinth
Fiend Bosses List and Locations How to Open All Kalpa Doors
Burial Chamber Guide List of Shady Brokers
Junk Shop List New Game Plus Features : How to Unlock NG+
Beginner Guides
Press Turn Battle System Guide Differences Between Difficulty Settings
How to Swap Demons How to Talk to Demons
How to Change Voice language How to Save Game
How to Remove Curses How to Farm Macca
Stat Guides
Stat Guide: All Stats Explained What Does Strength Do
What Does Magic Do What Does Agility Do
What Does Vitality Do What Does Luck Do
Where to Find Bill Should You Release Pixie
Jumping from Mantra Headquarters Demi-Fiend Canon Name
How to Open the Door in Ikebukuro Four Oni Locations


3 Anonymousover 1 year

bro me too wtf

2 Anonymousover 2 years

It opened for me with 25 base strength. No magatama equipped that increased my strength.


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