The story follows the Akaza family which consists of a father Shinobu, mother Kikuko and their children: Shinosuke Momoko and Sachi. Due to constanly fighting between Shinosuke and Momoko, the latter decides to move out. Brother and sister were very close in the past but Momoko's unplanned pregnancy have changed everything. However is it possible that Shinosuke still really care about his younger sister? (Source: MyDramaList) ~~ Adapted from the novel "Ani Imouto" by Muro Saisei.