At the age of 24, Maeda Shinshi is a standard white-collar worker who receives an untraceable love letter from an anonymous girl. Eventually, he discovers that the author of the letter is a bashful and somewhat bewildered elementary school student named Oyamada Nana. Despite his best efforts to make Nana feel at ease, he continually blunders and appears to be a creep. Can Nana find a way to express her feelings to Shinshi, and will Shinshi cease his actions that make him appear to be a predatory Lolicon?