We are lucky in the sense that we get to choose our last name (and cup size). In the real world, many of us are stuck with awkward names. Names that are constantly misspelled or mispronounced.
"Krisi" has no last name. If I were to somehow slip into the outside world as a female, I wouldn't be "Krisi" any way, I would probably use a feminine version of my male name and my actual last name. There's a name I would like to use that is the first name my mother would have given me if I had turned out to be a girl and a family last name, but my wife had a bad experience with a woman with that name in the past so it's probably not going to happen.