Tsukiko loves to sleep and spends every opportunity to do so. As a usual activity, she has slept at the school roof, however she finds a guy sleeping next to her! This same guy, also have asked her to sleep next to him in order to help him with his sleeping problems. This guy happens to also be that very popular guy that is the prince of the school. As they spend more time together, it's harder and harder for Tsukiko to get the sleep that she usually gets...