Sayoka partners with her twin sister Imari as one of Kaoru Kawahira's inukami, operating in near-perfect synchronization. They wear identical outfits and sport matching ponytails—Sayoka’s tied on the left, Imari’s on the right—while frequently finishing each other’s sentences. Though rarely at odds with each other, they fiercely compete to become Kaoru’s top-ranked inukami. Other pack members distrust them, labeling them sly and untrustworthy; in chapter 25, they manipulate Igusa into spying on Kaoru and Keita for a book project, causing widespread repercussions when exposed.

Both twins share identical physical measurements: 154 cm tall, with 79 cm bust, 57 cm waist, and 83 cm hips. Their similarity includes identical undergarments, revealed when Yoko used Shukuchi on them. Among Kaoru’s inukami, they appear infrequently but more often than Tensou.

Within the pack, others avoid sharing their rank to escape chore burdens or troublesome situations, implying the twins handle the largest share of undesirable tasks. They support Kaoru’s missions, participating in group techniques like "Purgatory" during spirit exterminations, though individual actions outside their twin partnership receive minimal focus.