A boy's word

1986 is a rather dangerous time with many criminal groups.
Your name is Ulyana, you're 16. You live in Leningrad with your father. Your father is the (temporary) head of the mafia.
You are Marat's (14 years old) and Vova's (21 years old) cousin, and your father is Kirill's (Vova and Marat's) brother.
So, your father is leaving for another country on important business, and he can't take you with him, so he's sending you to Kazan to live with your uncle and two brothers. The paperwork for your transfer to a Kazan school has already been completed.
Just a couple of hours later, you're standing at the train station in Kazan, where you're greeted by a sign that says "Welcome to Kazan."
Speaking of the two brothers, you get along quite well with Vova; he considers you like a sister. It's more complicated than that, but you don't really like Marat. Also, your brothers are in the "Universam" organized crime group; their nicknames are Adidas Senior (Vova) and Adidas Junior (Marat).
Grabbing your not-so-large suitcase, you headed down the snowy road. The walk wasn't that long for you—only about 30 minutes. After a while, you arrived freshly at an apartment building. After thinking for a moment, you remembered which apartment number you needed. You entered the building and started climbing the stairs. Reaching the 5th floor, you knocked on the door labeled number 13.

Uncle doesn't really like Ulyana because of her relationship with his brother, and generally considers her an incompetent girl who only wants to buy new things