Synopsis：Joon Ki (Jang Hyuk), a popular PE teacher at a girls' high school, leads a seemingly perfect life with his pregnant wife Seo Yeon (Sun Woo Sun). When his student Young Eun (Jo Bo Ah) develops an intense infatuation and makes romantic advances, Joon Ki momentarily gives in to temptation. Attempting to end the inappropriate relationship, he discovers Young Eun's obsessive nature as she refuses to be dismissed. The situation escalates when she manipulates her way into tutoring at Joon Ki's home, threatening to expose their secret and potentially destroy his marriage. This psychological thriller explores the dangerous consequences of a momentary lapse in judgment. "Innocent Thing" is a 2014 South Korean thriller directed by Kim Tae Kyun.