A trip to the beach turns out to be more than expected for two people who are mourning the losses of their beloved. Perhaps a mysterious girl known as the "Umi Warabe" can help them to heal their wounds and move on with their lives. Matsunaga Yoshihiro is the chaperone for a group of high-school students on a summer trip to the beach. One night he saves one of the students, Morisawa Nao, as she attempts to drown hers...