Since long ago, human civilization had lived on the ocean floor. However, there were many humans who wanted to live above the surface and they moved to land creating a fundamental separation between t...

On Christmas Eve, Hiro Hirono runs into Miyako Miyamura, a frivolous girl who "borrows" his bicycle in order to chase down a purse thief. After Hiro finds his bicycle wrecked and Miyako unconscious, t...