She was just embarrassed because she intended to ask Shigure to buy it for her.
Makes you wonder how did she mistake someone who's way taller and has different hair color, even from behind.
Can you buy one for me?Hey, hey.I, like, got the wrong person...
poiSorry having troubled you.She got one bought There was such a time tooShigure~Of course it would be okay. What would you like?Yuudachi-san really is cool and good looking-nodesu.Cool, huh...Few years agoShigure~There's ice cream in that shop over there!
PoiSuch a cute little sister you have.