Sōta's novelist sister Izumi enters a slump when she assumes he is dating Popura and will stop paying attention to her. She decides to go on a journey where she ends up meeting Mahiru who helps cheer her up. As Sōta looks after Izumi, Nazuna helps out at Wagnaria, which annoys Aoi who believes she is outshining her. After hearing about it, Nazuna puts on an act to make Aoi feel better about herself.

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.

Whilst Popuar is pleased to finally reach the report sheet, Sōta is horrified by the thought of her growing taller. Whilst talking about the future, Aoi ends up turning a statement from Popura that she might have to leave Wagnaria some time in the future to a rumour that she is actually quitting, which she spreads to the other staff members. As the staff have their concerns over this, much to the annoyance of Maya the bird, Popura is confused by their weird reactions to her. After Maya helps Popura with her worries, the truth about Aoi's rumour soon comes out.