Obsessed with the Walkie-Talkie

In 1979, Yin Xiao'en (played by Kim Hee-na) is a third-year student in the English department at Shilla University. She has always had a crush on her senior, Dong-hee (played by Park Yong-woo), and she dreams of a beautiful life, but Dong-hee likes another student. One day, by chance, Xiao'en discovers an old intercom. One night, the intercom suddenly receives a call from another boy. Surprised, Xiao'en starts talking to him. Through their conversation, Xiao'en learns that the boy also attends Shilla University and is named Chi-ren (played by Yoo Ji-tae). They arrange to meet under the clock tower the next day, but Xiao'en waits in vain as he does not show up. Meanwhile, Chi-ren also waits in the pouring rain for Xiao'en. When they talk through the intercom that night, they complain about each other. It is not until the following night that they realize they come from different times and spaces. Xiao'en lives in 1979, while Chi-ren is in 2000. Their cross-time conversations leave them both in awe. That night, they confide in each other about their feelings, and unwittingly, their emotions deepen. Chi-ren reveals to Xiao'en that his parents were also students at Shilla University, and that includes Dong-hee and Dong-hee's lover, Shan-mei...