You need a step-DOWN transformer, a 1:1 to 1 step down to convert 110 to 100.
Most home wiring in the US tests at 117.5 volts, significantly higher than 100 volts required by Japanese cabinets.
Unless the cabinet has an advanced switch mode transformer to convert both the game board and monitor voltages down, I would not suggest plugging it in without stepping down the voltage.
A 1:1 to 1 would convert 117.5 to 106.8 volts, a lot closer to 100 volts.
Ninitendo Sanyo monitors are notorius for blowing key components when plugged in without the step down transformer.