Caught with a severe fever, Tobio Ikuse, a second-year high school student, was forced to miss his school trip on a luxury liner with his schoolmates. Four days later, Tobio hears the news about the disappea...

Takashi Sone is living on his own while he is attending college. Out of the blue, his parents tell him that his sister, Mafuyu, is moving in to live with him and that she will be attending a high school in h...