Annyeong is the Korean word for hello, while oppa is the term women and girls use for an older brother or an older male friend, which is why the two words together sound affectionate rather than formal. Short clips of the phrase circulate online as a meme greeting, especially in fan edits, K-drama reactions and videos about Korean pop culture, where creators use it to signal a crush, a bias or a welcome. Its appeal is simple: the meaning is easy to grasp even for viewers who do not speak Korean, and the cute delivery makes it reusable.