Meet Sumire Ishikawa, a softmore in high school. She has a secret: She's actually a mermaid. With the help of the legendary medicine, the Aqua Drop, she's able to live a normal life in human form. However, one time, she saved a boy from drowning, and to protect her identity told him to forget about her. She didn't expect him to take the extra step of completely denying mermaids exist! Now she's got to deal with her identity, and also her love for that boy she saved, Takaoka. Includes 3 other stories. Seishun no Susume Ushiro Sugata Hikaretai Mizutama ni Somare!