The 'Ohayo, Onii-chan' or 'Buff Weeb' meme centers on the jarring and comedic juxtaposition of a muscular, often intimidating individual performing a high-pitched, stereotypical 'little sister' anime greeting. This trend gained massive traction on platforms like TikTok and YouTube, where creators would sync their intimidating physique with cutesy anime audio, subverting expectations for comedic effect. It highlights the overlap between gym culture and anime subcultures, celebrating the 'buff weeb' archetype. The meme is typically used to show that appearances can be deceiving or to lean into the absurdity of an ultra-masculine figure embracing kawaii aesthetics.