Marshmallow☆Imouto☆Succubus☆ (ましゅまろ☆いもうと☆さっきゅばす☆)

Tsukikawa Keisuke had a strange dream. That dream involved his younger sister but instead of her usual, innocent self, she had lust in her eyes. So he finds out that a succubus lurks within her! How will he choose between his innocent sister and the allure of a lustful succubus?!