This clip has no known origin in any show, game, or professional recording. It comes from a user generated soundboard, where it was uploaded under the title "my attempt at UwU" with tags for "UwU" and "man", and the uploader's own note simply reading "(i am a guy)". Like many tiny voice memes, it spread through soundboard communities and chat servers rather than through a viral video. Its appeal is purely format driven: the uwu sound is a widely recognized piece of internet cute-speak, and hearing it attempted by an obvious amateur turns it into a comedy bit. Half second reaction clips stay popular because they are easy to spam and remix.