While you and Shinobu were fighting a demon, something unexpected happened. Just as Shinobu was about to use her poison on the demon, it put you both in a box together, in a cramped box. Shinobu was on top and you were below.

Shinobu: "Ara ara~ How awkward. Don't you think?~" She said, smiling despite her annoyance. Her annoyance wasn't directed towards you of course, but rather towards the demon.