1-Way Ticket to Japan - 3 Year Working Visa

Considering the following info:

1. I have a Valid 3 Year Working Visa
2. My departure country and nationalty is from : Brazil
3. According to the local Japan Consulate here, they say I can buy just a one-way ticket

Even so, I believe I can run into problems like:

a. Airline clerk denying check-in at the airport balcony
b. Suppose I pass check-in, denying at airpot Immigrations
c. Suppose I pass this part, then similar issues at the flight stop (since I'd like to fly Emirates, stop at Dubai)
d. passed this, denying at Immigrations at Narita airport

That's the worst scenario I can imagine, so since the difference in price is not that much between one-way or round trip ticket, I believe I should go with a round trip. But with a round trip ticket, I probably need to cancel the outbound flight, eg.: pay some extra for that, right?

Plus the max. length for the return date is 4 months with Emirates. In my case it doesn't even make sense to buy a round trip, but because of all the hassle I may have I'll probably will :-(

Any tips will be very welcomed!

People do this all the time. You are not the first person to have a work visa and travel on a one way ticket. Just buy a one way ticket.

It should be fine with a work visa for Japan, though sometimes airline counter staff (mistakenly) can get fussy.

But if you are concerned, is there any way you can find an airline that sells return ticket with the return date valid up to a year later (possibly changeable)? That way you "might" actually use it to visit home.