Promised Pen

The Promised Pens are objects possibly made by William Minerva, which were either left behind at certain places or given to certain people for the orphans of Premium Grade Plantations to have the chance to find a safe place in the form of Shelter B06-32 or Goldy Pond, or originally an escape to the human world.

Origin
Not much is known about these pens aside from the fact that there are at least two pens which both serve as a key to the underground shelter. The oldest and first pen was left behind at a different plantation than the Grace Field House, possibly by William Minerva.

Function
The pen has at least 5 known functions:
 * Location: When the middle of the pen is opened, it projects a virtual navigation map for the orphans to find their way in and out the Grace Field House. It also shows their location outside the orphanage.
 * A key: The pen is the only known key to enter the secret Shelter B06-32 underground. It also is the only known key to enter Minerva's door in Goldy Pond.
 * Codes: The pen contains multiple unknown codes and messages.
 * Writing: The pen cannot be used to write with.
 * Pen Cap: Found in the Golden Lake, the cap is a 'memory stick' with updated data, and gives information about Demons and the Demon World.

The Map
The pen serves as a navigation map for the orphans to find their way in and out the Grace Field House. It gives clues on where to go in certain codes.

0-Area

 * 00-00 is where the Grace Field House is located.

A-Area

 * A08-63 is where Goldy Pond is located as well as the Goldy Pond Resistance. Inside, a windmill is a passage leading to a door that can only be opened with the pen.

B-Area

 * B00-15 is the place where the children ran off to after they escaped from the underground demon trap.
 * B01-14 is the location where the children fell into an underground demon trap.
 * B04-21 is the number shown in the underground tunnel that leads from the demon forest to a secret shelter.
 * B06-32 is the location of the underground Shelter B06-32 in the demon world.

C-Area

 * Unknown

D-Area

 * Unknown