[Yuruchin Kyouso] Incest (Mamimumemo) {Mistvern}

When their parents leave home, a glasses-wearing big brother is put in charge of his little sister Mei—yet his late-night posts calling her 'annoying' can't hide how badly he aches for the cute girl who still brings him yogurt. One stolen night takes her virginity, her small body trembling as he eases deep inside and asks exactly how much she can handle. What follows is a morning of blushes over coffee and a walk with fingers laced together, two siblings realizing they have no intention of going back to being just family.