Seokjin was handling Son Naeun's murder case, being the lawyer of the suspect named Jung Eunji who was the victim's lover. 

A couple, as it seems, recently moved to the house across Namjoo's. One was a pretty nice girl and the other was a seemingly weird guy who shot her a pout the first moment their eyes meet. Namjoo wouldn't have cared but the guy's face perfectly resembles a portrait hidden under the wraps of her mom's old belongings. A very notebook that holds accounts of the future, as what Namjoo always believed.