Boy, with Caution is an emotional drama film that follows Jang Gi U, a 32-year-old temporary high school teacher living under the weight of his past. Raised by a single mother who constantly pressured him to be flawless in the eyes of others, Jang Gi U grew up hiding his true self. However, his life took a devastating turn four years ago when he became the subject of an inappropriate rumor involving a student. As a result, he never took the teacher certification examination and has spent years moving from one temporary contract teaching position to another. To the outside world, he appears to lead a flawless and perfect life, but underneath the surface, his daily existence feels incredibly dull and unremarkable. This moving film explores the heavy burden of social expectations, the pain of past rumors, and one man's quiet journey to find genuine meaning in a highly guarded life.