Mystery of humanity continuing, and Lovers

Plot: Young-sook tests Mansu by asking, 'What if a prettier woman than me asks you out?' Mansu responds that he won't miss a good opportunity, but adds that despite that, you and I are each other's best match. However, Young-sook is not pleased with his answer. Mansu attempts to persuade her with a story, and the two return to their present after passing through an imaginary distant past.