Japan now hosts about 873,000 Chinese nationals, roughly matching Wakayama Prefecture’s population of about 889,000, and the number has risen steadily since 2000, spanning the wealthy, middle class and skilled workers to form a diverse landscape that resembles a “mini China.” WeChat and other networks connect people across borders, helping many Chinese live in Japan with limited daily contact with Japanese society. Factors include China’s policies and risks, plus migrants seeking safety and cost stability in Japan. While growth enriches Japan, it also fuels frictions—rising rents, debates over foreign researchers’ support, and high‑profile misconduct—that risk souring public sentiment. Many long‑time Chinese residents feel misunderstood or marginalized. Policymakers must pursue long‑term, risk‑aware designs, close loopholes, and consider civic‑integration checks, while Japanese society and newcomers strive to build a stable coexistence.