故事发生在日本国立科学与工程研究生院。一年前,该大学的冰室鸢尾将告诉她对同一研究成员Yukimura Tonight先生的看法。但是,他问道,“喜欢”的定义是什么?两人开始研究证明浪漫情怀。。After Carlos, an impoverished teen from a fractured home, receives a desperate note from Sarah, a pen pal he lost touch with a year ago, he uses her letters to solve the mystery of her disappearance and crimes she may have been a part of.。