Kokura Line (Kitakyushu Monorail)

The line uses the Japan-standard straddle-beam (Alweg-type) configuration, in which the trains ride astride a single concrete beam rather than hanging beneath a rail. When it opened it was, according to monorail historians, the first monorail in the world to combine high-level platforms with cars whose floors sat entirely above the bogies; earlier straddle-beam trains had carried their running gear within a podium that intruded into the passenger cabin. Placing the floor above the bogies freed up interior space, and almost all of Japan's surviving Alweg-type monorails have since adopted the same high-platform, podium-free arrangement.

The monorail opened on 9 January 1985, running from the station then called Kokura — today's Heiwadōri — south to Kikugaoka. The line was built and is owned by the city of Kitakyushu as an urban transit project for the Kokura district, replacing earlier surface transport in the corridor. From the outset it served the dense southern suburbs of the city, but its original city-centre terminus stopped short of the main railway hub at Kokura Station.

That shortfall was addressed in 1998. On 1 April 1998 the line was extended roughly three hundred metres from Heiwadōri directly into the Kokura Station building, giving the monorail a through connection to JR's Kokura Station; at the same time the former terminus, which had been named Kokura, was renamed Heiwadōri. The extension had been resisted by businesses in the Uomachi shopping district, who feared that bringing passengers straight to the JR station would draw shoppers away, but that loss did not materialise.

The Kokura Station extension proved decisive for the line's finances. The municipally owned monorail had not turned a profit in its first years of operation, and it was only after the 1998 link to Kokura Station was completed that the line began to make money, as the direct interchange with the national rail network lifted ridership.

In the decades since, the Kokura Line has remained a single-operator urban monorail focused on fares and service revisions rather than route expansion. A discount "100-yen monorail" ticket for short trips around the city centre was introduced in 2007, and the line adopted the "mono SUGOCA" IC smart-card fare system in 2015. The monorail also runs occasional novelty services, including a Santa Claus train on 24 December.

• 19859 January: the monorail opens between the station then named Kokura (now Heiwadōri) and Kikugaoka, the world's first monorail with high-level platforms and trains with floors entirely above the bogies.
• 19981 April: the line is extended about 300 m from Heiwadōri into the Kokura Station building, connecting to JR Kokura Station; the former terminus 'Kokura' is renamed Heiwadōri.
• 199818 May: a fare revision takes effect, with a base fare of 170 yen (150 yen between Kokura and Heiwadōri).
• 20071 May: the discount 'Monorail for 100 yen' ticket goes on sale for short trips to an adjacent station and between Kokura and Tanga.
• 20141 April: fares are revised in line with the consumption-tax rate increase.
• 20151 October: the 'mono SUGOCA' IC smart-card fare system is introduced and fares are revised.
• 20163 October: the size of the ordinary paper tickets is enlarged.
• 20191 October: fares are revised for the consumption-tax rate increase; a maternity discount and a one-day pass are introduced.