Cat God
Shiratama
Long ago, Shiratama chooses Yaya as his host and the two became inseparable since. She often calls him Nekogami-sama. This bond is the reason how and why Yaya becomes friends with many other Cat Gods. Yaya appears to be very dependent of Shiratama as she admits she's not able to do much without his presence.
Residents of Yuragi-sou
Fuyuzora Kogarashi
When Kogarashi first move into the Yuragi-sou, the first thing Yaya does is lick his cheek after being cut by Sagiri's kunai trying to heal it. Yaya wasn't originally very fond of Kogarashi due to their first encounters which include being accidentally peeped on and being touched in her cat form which she disliked. However, she eventually warms up to him after being fed grilled fish that he cooked for her and the other Yuragi residents. She became affectionate towards Kogarashi that some described as being tamed with food. She's among the Yuragi female residents who holds no romantic interest towards Kogarashi, but still is quite attached to him.
Yunohana Yuuna
Despite their few interactions, Yaya and Yuuna seems to be quite close to each other as fellow Yuragi inmates. Their bond is deep enough that she is willing to help the others protect Yuuna from Ouga.
Nakai Chitose
While the exact relationship between the two is unknown, Yaya appears to respect and care for the manager like the rest of the Yuragi residents.
Ameno Sagiri
One of the kunoichi of the Demon Slaying Ninja Army of the Ameno Clan and also her fellow room mate of the Yuragi Inn.
Arahabaki Nonko
The two are fellow Yuragi residents who don't mind each other's company.
Shigaraki Koyuzu
When Koyuzu moves to the Yuragi Inn, the two became good friends. The two share an interest in a Magical Girl anime, that on occasion they play Magical Girl where Yaya acts as Koyuzu's familiar.
Ameno Hibari
While their hasn't been much interaction between the two after Hibari moves to the Yuragi Inn, Hibari does find Yaya cute.
Schoolmates
Chisaki Miyazaki
When Chisaki visits the Yuragi Inn, Yaya becomes instantly attached to her after eating one of her Italian dishes.
Higurashi Nazuna
A friend of Yaya whom she knew since middle school.
Todoroki Shion
The two first meet as fellow first years in Yukemuri Highschool. While everyone was originally scared of Shion, Yaya wasn't bothered by her and becomes Shion's first high school friend after she tries to save a cat.
Others
Makyouin Ouga
The late 6th Yatahagane who was Kogarashi's master and also a ghost after her death prior to her battle against Garandou 100 years ago. In spite knowing Yuuna's alleged identity as a Garandou, Yaya and the Ameno Cousins attacks Ouga in order to protect their friend, but the Yatahagane's power is too much for all the three of them.