Why do people in Hong Kong and Guangdong call fast food "bento"? Do you know how this happened?

This is influenced by the popularity of Japanese dramas. At that time, many male and female protagonists would have lunch together and eat a "lunch box", which is what we usually call "lunch box" or "lunch box" to start their dating and meeting. Because Japan calls this portable lunch box "bento", with the gradual integration of culture, "bento" has become synonymous with "fast food". Just like "taxi" instead of "taxi".