후쿠오카 시 교통국
The is a subway line, which forms part of the Fukuoka City Subway system in the city of Fukuoka, Japan. It connects Nakasu-Kawabata in Hakata Ward with Kaizuka in Higashi Ward, all within Fukuoka. The line's color on maps is blue. Officially, the line is called . Like other Fukuoka City Subway lines, stations are equipped with automatic platform gates, and trains are automatically operated by ATO system.