Haruki Murakami's short story "Birthday Girl", available to read online, is about a girl working part-time as a waiter who gets to make a special wish on her twentieth birthday. Much of it is written from the third-person viewpoint of the girl herself, but (starting from the second page) there is also a first-person narrator in a many-years-later frame story:
Somehow she and I had gotten onto the subject of our twentieth birthdays—what sort of day it had been for each of us. Most people remember the day they turned twenty. Hers had happened more than ten years earlier.
Who is this character, and what is their relation to the girl? I didn't even spot any indication whether it's a man or a woman. At first I thought it might have been a romantic interest, but then at the end she talks about her family life, so apparently it's not even someone who knows her well.