The representative director of Kouei Corporation was involved in the company's operations, where workers engaged in hazardous tasks such as arc welding in indoor work areas handling welding fumes. On July 29, 2023, a specific chemical substance health examination was conducted by a physician. However, between that date and November 8, 2024, despite no legal exemption, the company failed to conduct the health examinations at the required intervals of once every six months. As a result, on May 27, 2025, Kouei Corporation and its representative director were each sentenced to a fine of 300,000 yen for violations of the Industrial Safety and Health Act.