Kajitsu 

Kyouichi and Shouma meet again on the beaches of Okinawa after parting nearly a year ago when their relationship as step-brothers ceased to be. Before their parent's divorce, Kyouichi kept his feelings secret all this time for the sake of their family, but can he keep them hidden when he's pushed to the edge under the sweltering summer sun. (Source: Shueisha, translated) Note: Includes three extra chapters.