The term 'waifu' originated from the Japanese pronunciation of the English word 'wife' and gained massive internet notoriety through a scene in the anime 'Azumanga Daioh' during the early 2000s. It refers to a fictional character, typically from anime, manga, or video games, for whom a fan has a strong emotional attachment or romantic attraction. The waifu meme culture involves ranking 'best girls,' playful debates over character loyalty, and the famous 'waifu for laifu' pledge. It has evolved from a niche otaku subculture into a mainstream internet phenomenon used to express intense fandom and character appreciation across all forms of digital media.