Kumamoto City will make December 24th a “Free Bus and Train Day” for one day only, making all local buses, Kumamoto Dentetsu trains, and Kumamoto City Tram lines free of charge. On that day, anyone can use the buses and trains as many times as they like for free.
Buses are eligible for free if they pass through at least part of Kumamoto City, but some routes (Airport Limousine Buses/Kumamoto Station Direct Buses/Aso Kumamoto Airport Direct Buses, In-prefecture Rapid Buses/Akusa-go/Takamori-go, Out-of-prefecture Highway Express Buses/Hinokuni-go/Yamabiko-go) are not eligible.
Please check the official website (PDF) for specific examples of routes that will be free and those that will not be free.
© Source travel watch