Hyun-jae, a 16-year-old escaping her abusive father, manipulates Hae-in, a woman searching for her missing daughter, into taking her in as a replacement. Over the summer, Hyun-jae bonds with Hae-in, finding peace through her love for singing, but becomes obsessed with becoming Hae-in's new daughter. When Hae-in learns her missing daughter may have been found, Hyun-jae, despite her fears, makes a selfless decision to accompany her, realizing she can't replace Yun-seul.

《纯情漫画》改编自人气网络漫画家姜草的同名作品。
30岁的公司职员金延寿（刘智泰 饰）每天上班乘地铁时总会遇见和自己抢位置的女高中生秀颖（李妍熙 饰），两人慢慢开始留意对方。一次秀颖上学时忘记系领带，便向延寿临时借了领带，两人的心因此慢慢地靠近。而因为进修同样的课程，24岁的孰（金英云 饰）喜欢上了比自己年长5岁的夏京（蔡贞安 饰），面对孰的爱情告白，有着悲伤爱情回忆的夏京婉拒了，在孰的努力下，夏京开始慢慢敞开心扉。然而因为年龄的差距，秀颖的母亲介入了这段恋情，而孰也因为夏京放不开原来的恋情而感到受伤。两段恋情都陷入了危机之中……
那么这两段两段纯情之恋是否能在这个夏末秋初的午后继续上演呢？