From there, it's three hours to Tokyo and 1.5 to Kyoto by train. But although Nagoya is not as popular of a destination as the other two — The Japan Times once called it "the most boring city in Japan," though far from everyone agrees — it's a historical and economic hub worth visiting on its own merits.
Luckily, roundtrips from the West Coast and Hawaii to Nagoya on Air Canada and United are severely discounted right now. According to Scott's Cheap Flights, you can get there from Los Angeles for $392; Las Vegas or San Jose, CA, for $412; San Diego for $414; and Honolulu, HI, for $518. Normally, these trips go for around $900. The fares are valid for August through October 2017. From Honolulu, they're also available through May 2018.
Definitely don't wait to book these flights: Scott Keyes, the founder of Scott's Cheap Flights, says they will probably only last a day or two. If that — they could disappear within a few hours.
Pro tip from Keyes: "For a day trip or overnight getaway, check out the traditional houses in the historic village of Shirakawa-go."