白孝安(韩智友 饰)出生于富贵之家,就读于贵族学校之中,是校内成绩排名第一的优等生。白孝安个性开朗乐观,总是一副笑眯眯的样子,拥有许多朋友。让大家都没有想到的是,这样热情活泼的女孩,竟然选择以自杀的方式结束了自己短暂的人生。白孝安的朋友们觉得事有蹊跷,决定调查事件背后的真相。 闵浩秀(洪宗玄 饰)是白孝安的前男友,刚刚提出分手没多久,白孝安就自杀身亡,因此他的嫌疑最大。徐毓(朴智妍 饰)偷偷的喜欢着闵浩秀,因此对处处都胜自己一筹的白孝安心存妒忌。随着调查的深入,众人才发现,在白孝安纯洁无暇的形象背后,是伸手不见五指的黑暗深渊。When a high school girl dies mysteriously, her friends decide to investigate the cause of her death. The second season has a similar focus to the first, dealing with current social issues faced by the youth both at school and beyond: friendships, family problems, pregnancy and educational corruption.