After losing their mother, sisters Yui and Riona were raised by their father. Riona hated their father, who was constantly cheating on her even before their mother was alive, and lived alone, while Yui took care of their father. One day, their father fell ill and was hospitalized, but Riona refused to meet him. Riona was in her father's arms. Yui was jealous of her sister and treated her coldly. However, Riona still loved her sister, and so she started to touch Yui No body, trying to bring her back to the kind sister she used to be...