Rika's apartment is a key location and where the player mostly resides in the game after being sent there by Unknown during the Casual and Deep Story.
Rika's apartment is registered under V's name, but is where Rika used to live in prior to the installation of the special security system. There is an elevator and a password lock by her room. The code used to unlock the door is only known to Rika, Unknown, and 707. In Yoosung's route, it is revealed by Seven that the place has good facilities with shower booth and a bath tub, there are also 20 bodyguards in the apartment who will put down any stranger in 3 minutes.
Zen's route reveals that the apartment has heat and motion sensors. Seven stated that Rika's room is on the 14th floor and the window is made with bullet proof glass. In Jumin's route, when the player asks if Seven is watching her sleep he denies it and states that he is watching her on a CCTV in the hallways. But in the normal and bad endings of Xmas Special, it is revealed by him also, that there are CCTVs around and inside the location, except in the room.
The player is given the address to the apartment location by Unknown, and she is asked by him to run an errand by entering it. Pretending not to see the password lock on the door will lead to prologue bad ending.
The apartment contains a special security system. In the prologue, V informs the player not to touch anything in the room else the alarm will ring. Furthermore, the apartment also contains private documents about the party guests. In Seven's route, Seven also finds blueprints of Mint Eye's building in one of the drawers. All routes eventually reveal that a bomb was placed inside by Seven at Rika's request to destroy the documents in the case an intruder attempts to steal the information.
The player stays in the apartment for the majority of the game; however, her safety becomes an issue as the days pass by. In Yoosung, Zen, and Seven's routes, Unknown hacks into the bomb to detonate at the presence of any member of RFA entering or exiting the apartment. He is also given a manual switch to activate the bomb.
Rika's apartment is destroyed by the bomb in Yoosung's Bad Story Ending 1, Bad Relationship Ending 2; and Jumin's Bad Story Ending 3.
In the second part of the Secret Ending, Seven makes an offer to Jaehee to purchase the apartment to use as RFA's office.