Lee Ha Na

The K-eldest-son and K-eldest-daughter meet while sacrificing themselves in search of happiness and love.

An AI programmer Ha-won has had a crush on his childhood friend Ji-soo for 10 years and cannot forget her even after she got married. Meanwhile, a sound engineer Seo-woo finds out about Ha-won's story by chance and slowly falls in love with him.

Set around an emergency 112 call center. During the golden time after a crime takes place, the call center chases criminals including a serial killer.