Ani ga Imouto de Imouto ga Ani de.Ani ga Imouto de Imouto ga Ani de; Ani-Imo; Big Brother is Little Sister and Little Sister is Big Brother; Братики-сестрички; รักลับ ๆ สลับร่าง; 亦兄亦妹; 兄が妹で妹が兄で。; 兄妹换换爱; 兄妹換換愛; 오빠가 여동생이고 여동생이 오빠고

Twins Hikaru and Youta are an odd pair. Youta loves to cook and help out his family while Hikaru is a dark girl whose own family find her on the creepy side. Their everyday life involves Youta cooking and doting over his sister with Hikaru clinging on him. Then, on their birthday, their life changes. Youta learns that he is not related to Hikaru by blood and, while chasing after her, they both get hit by a car. When they wake up they find out that their lives have taken an unexpected turn.