Sweet Spot Sunday: Booking intra-Japan airfare for just 5,500 United miles

United Airlines has historically had a large presence in Japan, with nonstop flights from a handful of Japanese cities to the U.S. It also has a close partnership with All Nippon Airways — ANA, for short — that operates flights both inside of Japan and to dozens of international destinations.

One of the ways United and ANA's partnership can be useful is booking domestic flights within Japan using United MileagePlus miles. This is particularly useful when considering how expensive these tickets get at the last minute or during peak travel dates. With MileagePlus, you can book many routes for just 5,500 miles.

This article will show you how you can redeem United miles to book cheap intra-Japan tickets. I'll start with an overview of the sweet spot and dive into a step-by-step guide to booking the award. Finally, I'll give you a look at how to earn United miles to book this award.

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Why it’s special

You can use United miles to book intra-Japan flights for as little as 5,500 miles one-way. This is an extremely low number of miles to pay for flights that are often expensive. For example, booking Tokyo-Haneda (HND) to Hiroshima (HIJ) two weeks from travel costs $185 one-way on ANA.

The same goes for other routes. For example, a one-way ANA ticket from Sapporo (CTS) to Osaka (KIX) costs almost $200 on some dates. Using miles to cover these expensive short flights gives you more flexibility in when and how you travel around Japan.

Both of these routes — and nearly every other short-haul ANA domestic route in Japan — can be booked for just 5,500 miles one-way in economy. Better yet, award space is plentiful, so it's possible to book these award flights on most dates.

That said, not all United awards price this low. You'll pay more miles when booking within 21 days of departure. For example, booking the same Tokyo to Osaka award a week from departure costs 6,000 United miles. This isn't a huge increase, but worth noting.

Further, some longer domestic Japanese routes cost moderately more miles. This flight from Tokyo to Okinawa (OKA) costs 8,800 miles one-way. It's still a good deal, but the added mileage cost is unfortunate.

Related: Cleared for Takeoff: Using points and miles for a birthday trip to Japan

How to book this award

You can book intra-Japan flights right on the United website. Just navigate to United.com, sign in and enter your search criteria on the homepage. Make sure to select the "Book with miles" checkbox to view award prices. You can also use the "Flexible dates" function to see a month's worth of award space at once.

You'll see all available flight options at the center of the screen. Plus, you can see a week's worth of award pricing at the top of the screen. If you see a flight you like, click the "Select" button underneath the flight's price and follow the on-screen prompts to finish booking your flight.

Related: How I helped a points and miles beginner book a trip to Japan

How to earn points for this award

Thankfully, it's relatively easy to earn United miles. One of my favorite ways to earn is by transferring Chase Ultimate Rewards to United. You can earn Chase points with select Chase credit cards and instantly transfer them to United at a 1:1 ratio. Here's a look at some of the best Chase cards and their respective welcome bonuses:

• Chase Sapphire Preferred Card – Earn 60,000 bonus points after you spend $4,000 on purchases in the first three months from account opening.
• Ink Business Preferred Credit Card – Earn 100,000 bonus points after you spend $15,000 on purchases in the first three months from account opening.
• Chase Sapphire Reserve – Earn 60,000 bonus points after you spend $4,000 on purchases in the first three months from account opening.

Related: How to redeem Chase Ultimate Rewards points for maximum value

Bottom line

And that's all there is to it. This is a straightforward United sweet spot to book that can come in handy on your next trip to Japan. It gives you more flexibility in traveling around the country while letting you save money and see more of the country. Keep this sweet spot on your radar during your next trip to Japan.