Suspecting the possibility that a killer is at the same school, detective Chu Ja-young (Shin Eun-kyung), with her rookie partner Kim Dong-wook (Eric Mun) search the school to find identical handwriting that matches that of the diary excerpts. When they finally find the matching one, they're told that Jin-mo, the student who wrote the text, had already died in a car accident one month ago.
Suspecting a killer is at the school, detective Chu Ja-young (Shin Eun-kyung), along with her rookie partner Kim Dong-wook (Eric Mun), search the school to find matching handwriting that corresponds to the diary entries. When they finally locate the match, they are informed that Jin-mo, the student who wrote the text, had already died in a car accident one month prior.