Unfortunately, Nicki has always hated the last name “Minaj.” In an interview with The Guardian from 2012, she said that her last name, Maraj, was changed by someone in the music industry when she first signed to a label. “One of the first production deals I signed, the guy wanted my name to be Minaj and I fought him tooth and nail,” she said. “But he convinced me. I’ve always hated it.”
While the artist isn’t a fan of her stage name, she’s not a fan of her birth name either. The artist thanks the interviewer from The Guardian for complimenting the first name she was born with, Onika, but says she doesn’t like it. “My rule is, whatever you were calling me four years ago [in 2008] is what you should be calling me now,” she says, “because I don’t like it when my family or close friends call me Nicki Minaj. To me, I’m not Nicki Minaj when I’m with them.”
Later on in the interview, the rapper explains that Nicki Minaj isn’t exactly her. It’s more of an alter ego and character she puts on when she’s performing or making public appearances. “I feel it’s like one big theatre piece,” she says. “It’s a show.”
Source : https://www.distractify.com/p/why-did-nicki-minaj-change-her-name