I am a US citizen with a US passport. I will be studying abroad in Seoul later in the year and I am required to apply for a D-2 student visa for my program. My study abroad program will last for around 4 months, however I was planning on going to Korea a month earlier than the start of my program and staying for another month or two after it ends.
Will I need to apply for a separate visa for that?
I know that Korea allows visitors to stay 90 days without a visa so if the total amount of days I stay before and after my trip is less than 90 days will it be okay?
Is it possible for me to use that same D-2 visa to cover the extent of my trip or will it only cover the days of my program?
Lastly, am I able to regain entry into the country if I were to take trips outside of Korea during my time there? I wanted to plan some side trips since the price of flying from country to country within Asia is so much cheaper than if I were to fly from the US.