Legend of the Blue Sea
푸른 바다의 전설 (original)
Starring Jun Ji-hyun, Lee Min-ho, Lee Hee-jun, Shin Won-ho, Lee Ji-hoon, Hwang Shin-hye, Choi Jung-woo, Na Young-hee, Shin Hye-sun, Moon So-ri
It's a drama and comedy show, and has a rating of 8.1 out of 10 from Imdb which is very high for this kind of show.
Watch it here
Not found streaming from Italy.