Buddhism is the only major religion in the world with a falling number of adherents, according to Pew Research Center estimates for 2010 and 2020. By contrast, other religions grew during that period. Most of the world’s Buddhists live in Asia, and more than 90% are in 10 countries. The decline of Buddhism is especially pronounced in East Asia, including China, South Korea and Japan. Across East Asia, many people who were raised as Buddhists no longer identify with Buddhism. Most of them are now religiously unaffiliated – identifying as atheist, agnostic or just “nothing in particular.” In Japan, for example, 40% of adults who were brought up as Buddhists are religiously unaffiliated today, according to a Pew Research Center survey in 2024. In South Korea, that figure is 42%. To understand how and why people are leaving Buddhism, Pew Research Center conducted interviews in Tokyo and Seoul with Japanese and Korean adults who grew up in Buddhist families. We chose a mix of older and younger adults.…