Atsuhiko is a university student majoring in marine biology. He doesn't go to university much and stays in a simple room that was converted from a storeroom in his parents' house, leisurely continuing his research. There is a presence that threatens Atsuhiko's peaceful daily life. That is his younger sister, Miu. When she was little, she was a cute little sister who followed Atsuhiko around, but at some point, her... see more