The Administration Building is located in the north end of the Magical Camp. It is here where all the camp's faculty have their personal rooms and offices. Under normal circumstances the building remains locked to the Magical Girl trainees, but through several methods Eric(a) can find their way in anyway.
Entry Methods
Well
The earliest method of access to the Administration Building. Using the Rope, Eric(a) is able to descend down the well in the middle of camp. Within the well, there is a passage blocked by a couple gates and switches. The southern switch can be jammed to stay on using either the Kitchen Knife or Screwdriver. It is recommended to use the former as it is acquired earlier and the latter has other uses as well. This passageway exits out in the Archives.
The passage through the well will become sealed if Eric(a) has been caught by Sophie or gained the Maid Transformation.
Y's Secret Room
By completing the Y Investigation event, another passageway is gained through a hidden cave and passageway. This exits into a hidden room behind a bookshelf in the Storage Room.
Authorized Personnel
If Eric(a) has gotten the Maid Transformation or the Cursed Wig, then they can simply walk in through the front door as they will be recognized as a maid and therefore staff. This of course requires having gained access to the building through another method first.
Ground Floor
There normally is nothing noteworthy about the hallway on the ground floor itself, however, if you have completed Isabelle's "Nothing Special" event, then Sophie can be found at nights outside Olivia's Office. If Eric(a) is caught by Sophie without the Maid Transformation, then they will receive a punishment unless they concede to allowing her to drain their blood. If punished, then the entryway from the well will be sealed and there will be a trip to the Punishment Classroom.
Speaking with Sophie again after giving blood or as a maid, if you ask her about why everything is locked and give her some more blood, you will gain the Director's Office Key. This is provided that you did not get punished by her previously, and did not already acquire the key from Giselle.
Archives
Technically a basement level, but the entrance to the Archives is on the ground floor. The well entrance will lead to here.
During Natalie's route you can find undelivered letters from Natalie to her father here, allowing you to trigger an event with her.
Isabelle's Room
Isabelle's bedroom. Most visits here will be as cutscenes during events involving Isabelle such as her affection events. It is directly accessible once, during the Medical Exam if you choose to steal Isabelle's panties for the potion.
Marianne's Office
Marianne's office for official business. While it looks mostly as one would expect the Director's office to look, there are also numerous empty bottles of alcohol in the corners, which admittedly are also expected since the Director in question is Marianne.
Eric(a) and the Cutie Knights will be called to Marianne's office several times through the game as part of events to be briefed or debriefed. It is also accessible through the use of the Director's Office Key.
On Natalie's route you can find among the bookshelves pictures of Marianne in bondage for triggering one of Natalie's BDSM events.
Marianne's Junk Room
A cluttered room full of various items and artifacts Marianne has collected over the years. This room is located behind her office and also contains several things for the player:
From a create near the center of the room Eric(a) can steal a single C-4 Package. From the bookshelves underneath the scrolls there is also the Bunny Print Panties.
In the back there is a genie's lamp. Rubbing it will let out the "Makeup Genie" who proceeds to have a bit of fun transforming Eric(a) through several forms before returning them to normal. After that she will offer you a wish that you can accept, or decline and immediately return her to the lamp. Choosing to accept gives you several choices, each of which she will end up turning down actually granting as you go through them. After that she will grant you the "wish" of giving a beautiful futanari genie a blowjob and force herself on you before returning to the lamp. After this Eric(a) will refuse to rub the lamp again, no matter what you chose.
The main feature of this room however is probably the blue chest in the back, which is in fact the Hungry Treasure Chest boss. Be very careful of triggering it, as this is a one on one fight with only Eric(a). Note that this fight will not trigger if Eric(a) is in Cutie Magic Transformation.
Olivia's Office
Olivia's office. Very neat and orderly compared to Marianne's office, a little spartan looking.
You will come here as part of the Medical Exam. Coming here on your own during Natalie's route will let you find her redacted personal records which lets you trigger an event with her.
Storage Room
A storage room full of various junk and clutter. The passage unlocked through the Y Investigation exits here through a secret room behind the bookcase.
During Natalie's route you can find a stack of old BDSM magazines which unlocks another of her BDSM events.
Upper Floor
If the Alaska Mission has been completed then you can find Daisy in the corner here next to Marianne's room. Speaking with her will have Eric(a) tricking her into unlocking the door.
Marianne's Room
Marianne's bedroom, and fairly messy as you would expect from her. It would probably be even messier if not for having the junk room behind her office to move some of her other clutter to.
Two objects are of note here. The first that you should make sure to inspect first is a piece of paper in front of the cloth basket. Reading it will unlock the Temporary Prison. The other is a red chest on a table labeled as cursed. Choosing it to open anyway will get you the Maid Transformation and have Eric(a) subsequently clean up the room, including the piece of paper with the dungeon location (now neatly put on the table). Marianne will show up after you tidy up the room, give you the Maid Café Flyer, and kick you out. This also results in her sealing the well entrance, so make sure you read the memo first. If Eric(a) does not have the Blond Hair Transformation then they will realize that the maid headband is actually attached to their wig, removing it to gain the Cursed Wig if Acceptance is at least 10, or throw it away otherwise.
Olivia's Room
Olivia's bedroom. The only time you get in here at the moment is during an event where you encounter Olivia in the Library where she subsequently collapses from overwork, and Eric(a) helps to carry her back here.