Park Jimin, a medical student, became a surrogate in exchange for millions of won - all to save his mother after her heart surgery. To fulfill the contract, he had to spend one night with an unnamed billionaire and give birth to his child. After that, he left the country. Five years later, when he comes back, he is a completely different person What will happen to Jimin now? What kind of surprises are waiting for him? Who is the man he spent that night with? And where is the child?