Chanyeol is a self destructive doctor and Junmyeon is sweet, push-over nurse.

Sehun comes out to his very straight friends who then tries to find him a man.

  Luhan seeks treasures and finds a peculiar map for letters.

Sehun is a confused, bored university student with absolutely no motivation; so when his mythology professor comes up to him and invites him to a dangerous journey of finding the lost city of gold, Sehun takes it. 

Maybe Luhan can be the color of Minseok's black and white perspective.

Minseok is one of those oblivious otakus and prances around happily expressing himself. Luhan is one of those stuck up snobs who have everything and prances around with his nose in the air.