Raiden Mei is one of the main characters of Honkai Impact 3rd, the action role-playing game first released by miHoYo in 2016, and Kiana Kaslana is its energetic protagonist. Early in the story Kiana regularly addresses Mei as senpai, a respectful but affectionate form she keeps using as their bond becomes central to the plot. Fans clipped the short call as a standalone soundboard button, sharing it in edits, streams and fandom chats. It remains popular because a single familiar call instantly signals Kiana, her devotion to Mei, and early Honkai nostalgia.