tokyo , osaka and rinnai all are same ,,,,,, 100% same from inside out,,,,,,, all made by rinnai japan ,,,,,,, the one runs on natural gas has 12A/13A mentioned on label pasted on back side ,,,,,,,,, and the one runs on LPG has LP or LPG written back label ,,,,,,12A and 13A is a type of domestic gas used in japan ,,, they did not name it sui gas or some thing similar ,,,,, just like refrigerants have names 134a , 410 , R12 , R22 ,,, in same way they have 12A and 13A,,,,,,,
and yes they consume lot of gas ,,,,,,, couple of years before i did measure it but did not remember exactingly ,,,,, i even weight the cylinder after 1 hour running ,,,, and i dont think it was more then 1.5 hour per KG ,,,,,,,,,