To Hee-won's dismay, the BFF she crushed on and her other BFF are now dating! Seriously bummed, Hee-won decides to go wild just one time, and find solace with a handsome stranger. A very satisfying one night affair has now turned into more—she's pregnant! Fate brings them together again, and now the regimented Doo-joon is determined to do the right thing and marry her. But they're basically strangers! Except... their bodies have been very intimately acquainted. What's this mother-to-be to do?