The best price found from United States to Shikoku is on September 25th, 2018, travelling with China Airlines. See more options, compare prices and book: search flights.
Air connections are constantly changing, so check for the latest.
Takamatsu has direct flights to Taipei, Seoul and Shanghai; Matsuyama has direct flights to Seoul and Shanghai.
Domestically, All Nippon Airways (www.ana.co.jp), Japan Airlines (www.jal.co.jp) and a growing number of low-cost carriers such as Peach (www.flypeach.com) and Jetstar (www.jetstar.com/jp/en/home) have services that connect Matsuyama, Kōchi, Takamatsu and Tokushima in Shikoku with Tokyo, Osaka and other major centres.