This sound is associated with Hina in BanG Dream, also known by fans as Bandori. Short character voice clips like this spread widely through anime meme pages, fan edits, and reposted reaction videos because they are easy to recognize even outside the original scene. Its appeal comes from the exaggerated cute delivery of “Onee-chan,” which fits sibling jokes and affectionate teasing. It still gets used in anime-focused content alongside other familiar reaction sounds such as onii-chan, onii-chan when creators want a distinctly anime-style punchline.