Yoo-chan is a handsome, genius and selfish CEO of the successful IT company. But he has face blindness since he’s abandoned by his mother in his childhood and he is missing his first lover who left him suddenly. One day, a lovely girl like a tomboy, having good memory joins his company and works with him. He feels strangely drawn to her and he slowly changes into a warm-hearted person because of her. They run into each other they open their eyes to love and begin a romance like dark chocolate-slightly bitter but makes you crave for more.