In this scene of the anime, Hiyoko has basically drugged everyone with Teruteru's aphrodisiac soup so all the characters are all hot and bothered and not acting how they normally do. Please refer to the video in the casting call's description for more details.

Ibuki is the ultimate musician so she's naturally very upbeat and outgoing. Unlike most of the other characters, her natural personality continues to show even after consuming the sexy soup. For her line, she sounds more excited than anything else, albeit more breathless than normal.

Ibuki should be voiced by a female with mid-high voice range. I personally prefer her game voice more than her anime voice so I'll be looking for people with voices similar to that, but exact voice impressions aren't by any means mandatory. I'm mainly just looking for someone who has the voice and energy that stays true to her character.

Voice reference:

https://www.youtube.com/watch?v=vMNUQ1Iu8dM