On February 5, 2023, the passenger and auto ferry 'Ferry New Koshiki' operated by Koshikijima Shipping Co., Ltd. collided with the quay wall and movable bridge when departing Sato Port. On March 31, 2023, the ferry 'Yui Line Koshiki' also collided with the movable bridge upon arriving at Sato Port. Audits conducted by the Kyushu Transport Bureau's Marine Operations Supervisor on February 14, July 16, and August 5, 2023, confirmed violations of the Marine Transportation Law and the Ship Safety Law. On March 5, 2024, the Kyushu Transport Bureau issued a transportation safety order to the company, including the requirement that vessel owners must conduct temporary inspections under Article 5 of the Ship Safety Law before operation if there is damage affecting seaworthiness or safety of life.

On February 5, 2025, the passenger and auto ferry 'Ferry New Koshiki' operated by Koshikijima Shipping Co., Ltd. collided with the quay wall and movable bridge when departing from Isaki Port. On March 31, 2025, the ferry 'Yui Line Koshiki' also collided with the movable bridge upon arriving at Isaki Port. Audits conducted by the Kyushu Transport Bureau's Marine Operations Supervisor on February 14, July 16, and August 5, 2025, confirmed violations of the Marine Transportation Law and the Ship Safety Law. On March 5, 2026, the bureau issued a transportation safety order requiring the vessel owner to conduct temporary inspections under Article 5 of the Ship Safety Law if damage affecting seaworthiness or safety occurs, prior to operation.