Yoon Jin meets Min Joon’s private tutor, Kim Eun Young, through a very strange encounter. Yoon Jin has originally thought that her son was kidnapped, but it turns out that Min Joon asked Eun Young to stitch up his doll without his mom’s knowing. Although Eun Young is officially hired as Min Joon’s private tutor, Yoon Jin still does not trust her entirely and decides to keep an eye on her.