According to MANA, The calls are related to the itineraries of the Quantum of the Seas, Mariner of the Seas and Ovation of the Seas up to June, 2017 with calls in Busan, Jeju and Seoul, Korea replaced by those in Japan.
The move was triggered by South Korea’s deployment of Terminal High Altitude Area Defence (THAAD) missile system in cooperation with the United States, which Beijing believes is targeted against China, and not as a means of keeping nuclear threats from North Korea at bay.