Jeju island air ticket plus hotel

Jeju Island is exempt from visa. You can travel to Jeju Island with my passport, round-trip direct air tickets and hotel reservations in Jeju Island.

However, if tourists want to go to other cities in mainland Korea, they must apply for tourist visas. According to what you said, you must apply for a Korean tourist visa to enter Seoul.

If you apply for a tourist visa, you don't have to worry about the hotel and the ticket confirmation letter.