Adult PC Game: I become small to be comforted and taken care of by gentle Kasumi by Norn Archive

Not knowing each other since, the protagonist is the younger brother of three sisters who live near the hotel. He is modest, and this was corrected by the second girl inventing a cure for drugs. However, something went wrong and the main character becomes small! The three sisters love him and offer him to choose the one who will take care of him until he recovers. This time, the older sister, Kasumi, does it. Beautiful and full of maternal lines, she loves you unconditionally. Enjoy the life of a doing it with a gentle woman!