The campus' 2nd Year Heartthrobs: Arang and Hanse. After accidentally having a drunken one-night stand, Arang feels very awkward and keeps avoiding Hanse. Hanse, feeling tricked, starts to pick on Arang to get back at him ever since they bumped into each other in class. Stressed out of his mind because of the constant nuisance, Arang ends up fainting and is taken to the hospital, only to get the very unexpected news... "I'm pregnant? But I'm a male." On top of that, Hanse is the father?! As the news of male pregnancy spread, specialists began approaching them for research. Arang and Hanse, who are now research subjects, unwillingly start living together...