I would love to travel to Tokyo.

What are the off-peak travel months? What are the best sites for bargain flights to Tokyo?

When I was planning my trip to Europe I saw quotes for flight to Tokyo around 1,000 dollars in early summer.

You can do better than $1000.00. Where are you flying from?

Late January through mid-March, Late August through mid-October. Late November - early December. Times of year when the weather is not especially nice, basically. There are frequently good deals, though. Even from the US East coast you can find fares around $600.00 on occasion.

I found a fare online from SFO to Tokyo during december for around 783 dollars.

Would that be a good price for that time period?

It's not bad I don't think. It could go cheaper, but really no telling...fuel prices, surcharges..etc. If the $783 includes taxes and surcharges it's good I think.

Another thought, though. It's a bit early yet for discount fares to have been released. Check the terms and conditions and fare rules of the ticket carefully to be sure you understand how to change it if the price goes lower, paying attention to how much it costs to change it.

When I was planning my trip, the helpful folks on this forum suggested I wait for lower fares. They were right, and I ended up paying about $330.00 less per ticket.
I did monitor the fares every week or so, and when the price dropped, I jumped on it. (Although, looking at KimJapan's response, it looks like we traveled during a low season.)
Also, if you can fly on a Tuesday, Wednesday or Thursday, the fares are lowest.
I'd try a site like travelzoo, where you can get the best prices for several carriers.

That's a good price, but it is a bit early.

Last half of May is a good time, purchase in Feb or March.

Even now, you can get a rt for around $720 dep 5/24 returning 6/1, e.g.

And if you have flexibility in your travel dates, United often has flights from SFO, LAX and SEA on it's specials for purchase just a week or two in advance.

My sister and I are going to Japan in mid-June from New York. I bought the tickets about 6 weeks ago. We are flying direct to Tokyo and returning from Osaka through Chicago to New York(no direct flight exists from Osaka). The airfare on United was $860. The fare is no longer available on United but American is offering something similar

We flew American in March- if it's a direct flight they have all 777's which are nice and big.
Our flight had the screens in the back of the seat in front of you. There was more room than I thought, and the attendants were very nice.
If it's a good price, I say go for it.

A good site to watch fares for travel from US to Japan is www.iace-usa.com

Just plug in your home airport and desitnation and check the fares listed. Check back regularly to see how the fares fluctuate and which airlines are running specials.