Yu Ha Na has a trauma related to murder. She then witnesses the new teacher's murder scene.

The mystery club called Logic Tree investigates mysterious events.

Doppelgangers. Mice that take the form of humans. With murder intent, the look-alikes and the originals are both pressured to fight in their own ways. After an ambiguous event in their life, Ji-Suk and So-Hee's love life has been shattered. While trying to reconcile with her, Ji-Suk meets her look-alike, and that's how this story starts. What will he do when he, too, has a look-alike destined to kill him? And what's the secret So-Hee will never tell?

A contemporary story where fairy tales (Wizard of Oz, Snow White, Beauty and the Beast, etc.) suddenly gets mixed up with reality.