The "optimisation culture" refers to a mindset focused on maximising output for minimum input, which has become a defining feature of modern society. This is reflected in the global popularity of terms that evaluate cost-performance, such as "性价比(Xìngjiàbǐ)" in China, "가성비(Gaseongbi)" in Korea, and "コスパ (Kosupa)" in Japan. This culture of "optimisation" is applied to a wide range of situations, from mundane purchases when shopping to major life choices like careers, education, hobbies, and even relationships, framing all aspects of life as a problem of efficiency to be solved.