What does it mean when a girl calls a boy Agassi?

It means "uncle".

For older people, it will be called Agassi. In addition, when Korean girls like a boy who is too embarrassed to call him Oppa, they will jokingly call him Agassi.

Usage of oppa (brother)

1. South Korea used to be a society where men were superior to women, and women were always at a disadvantage. Korean women hope that men will treat their sisters like brothers in their own homes. I like to call my lover "Oppa".

2. Korean boys generally have to serve in the military during their sophomore year of college, which usually lasts about two years and two months. After completing their military service, boys will continue to return to their original schools to complete college, so boys are 2-3 years older than girls in the same class. In this way, when men and women in the same class fall in love, girls will naturally call boys "oppa".

3. "Oppa" is a term that expresses intimacy, making each other feel friendly. Girls will also call their ex-boyfriends "Oppa". Boys who are one or two years older than themselves and are familiar with them, and boys they have a crush on, will also call them "Oppa". However, for people who are not familiar with him, even if he is older than himself, he rarely calls him brother.