是一部以「百合之原高中」為舞台的校園懸疑劇。描述了這所學校里一直流傳著「百合子」的傳說。天才女高中生島倉美月，為了解救不慎捲入鬥爭的摯友矢坂百合子。她下定決心，要查出連環死亡案的真相以及傳說之謎的故事。

故事以爱慕着校园女神「苇月伊织」的平凡高中男生「濑户一贵」为主视角展开——暗恋伊织的一贵总是在脑中进行各种工口妄想，表面上却对伊织很冷淡，在一次契机下两人终于消除误会，彼此的距离逐渐靠近……

该剧讲述了转校生香川真琴(芳根京子饰)为了使表参道高中合唱部重现往日辉煌而奔走努力的青春故事。

Yuri Kashiwaga was once known as a genius pianist. One day, she returns to her hometown in Goto Islands from Tokyo. There, she begins to work as a temporary teacher at a middle school and advisor for the school chorus. The chorus aims to take part at a competition. Yuri gives the members of the chorus members an assignment. She instructs them to write a letter with the title of “To myself 15 years later.” The 15-year-old boys and girls write about their secrets and worries.