Sis, You Can't Run Away When We Haven't Cleared Up This Misunderstanding

“What a coincidence, Ms. Su!”

Su Wan ran into her student Lin Yang in a university classroom, only to discover that Lin Yang was the person she'd spent one passionate night with. Forced to quit her job, she had no idea she was pregnant. When they meet again five years later, they're surrounded by misunderstandings. Where can a relationship that began with a “mistake” possibly go from here?