寫作遇上瓶頸的小說家震明，在咖啡廳看見一個前來應徵工作的日本女孩。靈光乍現的他，決定為這個女孩創作三段不同的故事，隔壁桌的客人、收銀員、店長都成了他筆下的人物。這個女孩叫米卡，不論她是什麼角色，都無法忘懷與她激情的那一個夏日…

A noise is coming from the floor upstairs. Eunsu, hears this for over a month which causes uncontrollable anger to rise up. She gets eliminated again from a competition she had prepared for a long time. Eunsu decides to write her last piece with the theme of the noise between the floors and persuades her friend to help her follow and track the secret.