I wonder if his mother meant to name him "Armani?"
Omoni, in Korean, is a formal way of saying mother. Omma would be informal. For instance a woman may refer to her mother in law as omoni.
His mother is from Jamaica, and when she was asked what the baby's name was, she said, "Oh, mon, 'e..." and she started coughing, and couldn't finish the sentence, and the rest is, as they say, history.