It is suspected that technical trainees with poor Japanese language skills have asked Vietnamese nationals who have lived in Japan for a long time to take the tests on their behalf. The presence of their intermediaries has also been confirmed, and the prefectural police believe that such cheating methods are widespread within the Vietnamese community in Japan. The issue first came to light after The Japan Foundation, the organizer of the Japanese language test, grew skeptical over the prominently high pass rate at the Osaka exam venue when the rate normally stands at around 40%. At one point, almost all examinees at the Osaka venue were passing. This led the foundation to suspect that impersonators were taking the exams in Osaka. After being consulted by the foundation, Osaka Prefectural Police arrested a 31-year-old Vietnamese woman in December 2024 for allegedly taking the test by posing as another individual. "I've done it 10 times or so," the woman was quoted as telling investigators, raising suspicions that proxy test-taking is rampant.