Beautiful and intelligent, Bong Soon (Yoon So Hee) is nearly perfect, except she's a cyborg! And on top of that, she has a peculiar fail-safe built into her system-one that causes her to shut down as soon as love stirs in her cybernetic heart. But despite this design flaw, Kim Joo Sung (Cho Kyu Hyun), a whiz programmer, sets out to write the ultimate code for romance.