Who is the mysterious man who can't remember his past? Jo Hae Ji (Jung Ye In) studies hard in college to be able to fulfill her dream of making it into the Navy. She goes to work with Navy lieutenant Sung Ki Soo (Goo Ja Sung) for the Underwater Demolitions Unit (UDU). When Hae Ji meets special agent Jung Cha Ki (Jo Ki Sung), can she help him recover his lost memories and figure out his true identity?—Rakuten Viki