Umi used to be a very sickly girl when she was young. One time, she was on the verge of death after contracting a high fever, but then her fever magically disappeared, leaving behind a star-shape mark on her forehead with the color of the ocean. Now a sixteen-year-old girl, Umi dreams of finding love and having a boyfriend like many other girls her age. There's one guy at school whom she's really interested in, but things don't really go the way she wants them to, with another guy showing up out of nowhere... Not to mention, that guy isn't just your average guy.