Ah, ma sœur !

Sōta becomes depressed when he discovers Nazuna has grown as tall as him and has Popura act like his little sister for the day. Mahiru becomes jealous of this and works with Hiroomi to try and get Sōta to call her cute. The next day, Kirio comes to Wagnaria to look for his sister, but finds himself coming into conflict with the men, whilst Hiroomi attempts to keep him and Aoi from meeting each other.