Something isn't right here. Where is the manual/wiring diagram/schematic/ model/part/serial number?

Pay for someone that knows what they are doing. You don't!

It could, just maybe, be a two-speed two-winding motor, with ground, common, winding1 and winding 2 connections.

(Or something else.)

Some ohmmeter checks might be informative.

perhaps the other two are for a start/run cap!!

check connection info supplied with motor.

We need as much information from the motor plate as possible, as well as wire colors and any tags on the wires. Guessing might harm the fan, use excess current, or overspeed the motor.

How do you know that one of those wires is earth/ground?

If you can, supply a photo or two of the whole motor and the wires (terminals).

If you have a multimeter, measure the resistances between each wire and all the others. Also measure the resistance from each wire to the motor frame.

Japan uses same wiring system as USA, ie 2 phase 3 wire, one neutral and two 100V live wires 180 degrees out of phase (+/- 100V say) for a total 200V. Fourth wire is earth as in MEN (Mutiple-Earthed Neutral) system.

Jap and US are both 60Hz, so no need to worry there.

If you want to connect this fan to the US system, either

you will need a transformer with centre-tapped secondary winding to provide a total 200V (100 + 100), or

you will have to use both 115V phases and put a resistor in series with each phase to drop the volts under load to the correct value.

OP said the motor badge was marked 1 phas..

No point guessing until OP comes back with more information.

What does motor nameplate say? Specs. may have typographical error.

Measure the resistance between each terminal. You'll find something like 80 to 100ohms and 120 to 150 ohms, and a total of 200 to 250ohms. The bigger the motor the smaller resistance you can expect.

There are two windings with a common connection. Connect the common to neutral, connect the low resistance to Live, and connect the other in series with a 2 to 4MFD capacitor rated for 350vac or above.

It's a capacitor run motor, the main winding has less resistance than the phase displacement winding so needs a capacitor in series, not too critical in my experience. Megger to earth to test the windings and check the earth is solidly connected to the frame. Keep an eye on the temperature for the first 24 hours if you are connecting to 220vac & 50 Hz. Should be OK we had some that were stalled with dust & grease for months and nothing happened.