Soloist of the PrisonOri no Chuu no Sorisuto, 檻ノ中のソリスト, 笼中的独舞者

In a prison so big that it is called a city, all sorts of criminals have been amassed. Due to the inescapable walls, the population only continues to grow. Within are a pair of siblings - a young girl and a recently born boy. What will be their fate in this desolate, cold city...? A story of hope and struggle begins.