(C91) [squeezecandyheaven (Ichihaya)] Imouto wa Sickness

Aww jesus Oniichan... So for anyone who can't read Japanese, the sister is sickly and can't leave the house. Due to that, her and Oniichan got pretty close. Obviously if you're on this site. However, the mom turned out to be poisoning her daughter with said "medicine". Police show up at the end and break the truth to him. Tell him if she stops taking the medicine she'll get better. As he's returning quite stunned by this series of events, it shows the little sister saying she almost forgot to take her medicine which causes him to pause for a moment, before telling her to ensure she doesn't forget to take it. So he has gone from someone who cares about her to considering the options of keeping her locked up in the house sickly so he can continue "taking care" of her... She'd have still loved you without continuing the poisoning on your own. :( Here's hoping he only did that to momentarily keep the status quo together until he can break the news to her, instead of genuinely doing this.