One-day tram passes are also valid for travel on green-coloured Shiei buses (but not other city buses), which are handy for connecting between the tram and outlying sights or zooming between JR Kumamoto station and the bus centre.
The small Castle Loop Bus (¥130) connects Kumamoto Kōtsū bus centre with all the sights in the castle area at least every half hour, between 8.30am and 5pm daily. A one-day loop pass (¥300) will get you a discount at the museum and other establishments.
Kumamoto’s tram service connects with all the major sights. Single fares range from ¥130 to ¥200. A one-day pass (¥500) allows unlimited travel, and can be bought on the trams or in front of Kumamoto station.