“I’m all you need right, Nii-san?” My parents remarried and I got a step-sister two years younger than me. However, my step-sister became a shut-in after being bullied in middle school. In order to get my shut-in step-sister to open up to me, I, as her older brother, made a lot of attempts and as a result, I was able to get her to let me into her room……. “―I, have become unable to live without Nii-san♡” As a result of comforting and continuing to act as her big brother, Before I knew it, I found myself facing advances from my affectionate and sometimes aggressive step sister every day. ※ It may take some time for the yandere tendencies to fully develop. Enjoy the anticipation while reading through the beginning stages.