Translation:Where is your apartment?
usually shows depict relationships between people who are already close to each other, or become so over the course of the narrative. I'm not an expert on Japanese etiquette but i think degree of intimacy has a lot to do with how rude it is to address someone with kimi/anata/omae etc.
Levels of rudeness: (not in order) Kimi- rude (can be used lovingly in a couple) Anata- kinda rude, but default when name is unknown (can be used lovingly in a couple, like darling) Kisama- super condescending Omae- rough, tough, picking a fight (boys sometimes use this between one another to look cool or something) Omee- more rude than omae, basically swearing Temee- super duper rude, like calling someone an a-hole
It's safer to replace "you" with the person's name.
As far as I know, friends won't care much if you use anata or omae or something, especially if you're close.
Also, anime is a super exaggerated form of life. Don't take it seriously!
P.S. I'm not a native Japanese speaker so if I'm wrong please correct me.
The word "building" is not necessary, since it is obvious it is a building, just like in most places you would not call a condominium or shopping mall, "condominium building", or "shopping mall building".
Sometimes the question is not asking about which area is the building, but the actual address.
For example, a security guard can stop and ask someone he does not recognize where is the apartment, like which level, what unit number, if someone claims he lives in the building but could be a burglar or trespassing. Or by a policeman patrolling the neighborhood