Misaki (24) works at a flower shop. She has little experience with men and is not used to them. When she returns home after work, where she lives alone, her younger sister and her boyfriend are waiting for her at the entrance. She learns that the love hotels are fully booked and that she has nowhere to stay. Misaki decides to let them stay at her house. One night, after they've gone to sleep, while she's taking a shower, her younger sister's boyfriend bursts in...