Chapter 089.5 is eighty-ninth.fifth chapter of Volume 15.
Nanami was going back from shopping when she hears the backoning of a takoyaki stand. She hesitates but goes and stands in line. She gazes melancholicly at the happy families also waiting in line. When it was her turn, she orders five portions of takoyaki. Back home, Tomoe is mad that Nanami had taken so long. She shares the takoyaki and remembers what someone had said to her in the past. "This is the only moment you will ever be alone. Later on, you will become a lively person causing headaches as shrine-god." She comments to herself how spot on it was.