Yayoi has a fear of heights, to the point of screaming and crying for help when trying to look down at the ground (even when on an airplane).
Even though Yayoi is a very cheerful and optimistic girl, when angered (which almost never happens except with Hibiki and her younger brother) she is extremely ferocious and violent, though when it comes to Producer she refrains from yelling due to being scolded in return.
Alhough Yayoi dislikes wasting money, she loves to eat. If she can, she often goes for seconds or even thirds during breakfast and dinner. Despite this, she is surprisingly not selfish and loves to share her food with others.
It is very rarely hinted that Yayoi is secretly a pervert. Yayoi doesn't seem to mind being inappropriately touched or groped by Producer; in fact, she seems to like it in a few communication events (and her tension rises). Yayoi also rarely inappropriately touches Iori Minase
If Yayoi comes across a vending machine, she will dig in the change slot or under the machine, searching for spare change.
Yayoi is best friends with Iori, but it isn't explained how she and Iori became friends, or how they first met
