There is a treasure as precious as a national monument: the "Clock Tower of Stars," built by the Great Star Twins. Rumor has it that if you make a wish at midnight on the day the stars shine brightest, it will come true, leading people of all ages to gaze at the sky every night. However, a murder has occurred at that very tower. A body was discovered with its head completely shattered.

In response, the Seonghwal Police Station formed a Mystery Investigation Unit—MIU for short—separate from other teams, led by Sleepground, to conduct the investigation. The MIU members arrive at the scene and begin their search.