Gintama Season 4 Episode 15

The city is hit by a bad flu one winter day. Even Otae is sick with the flu. Shinpachi gets some long-awaited time alone with his sister and is tending to her when he gets a visit from Gintoki and Kagura. Turns out the two have also caught the flu and want Shinpachi to look after them. Irritated by Gintoki and Kagura’s abrupt visit, not to mention their selfish demands, Shinpachi is surprised when even more sick guests arrive.