Hiyori is a short, blonde haired girl who normally wears her hair up in two pigtails. When she was a Shinigami, she wore regular Shinigami's robes, with the 12th Squad's Vice-Captain badge around her right arm.
As a Vizard, she wears a pink tracksuit with a white vest, and the first kanji letter of her name is on her tracksuit jacket.
Hiyori is very short-tempered, and gets ticked off at almost any little thing. She gets worked up easily at laid back people like Kisuke Urahara and Shinji Hirako, and also dislikes indecisive people.
Hiyori barely shows any emotion to others, she only shows her anger mainly.
As Hiyori is a Vizard, she can gain the abilities of a hollow, like Ichigo Kurosaki, when she brings forth her hollow mask. As for her Zanpakutō's powers, they are currently unknown as Hiyori is yet to appear in battle. She is, however, very good at hand to hand combat. Not much else is known.
Hiyori was the Vice-Captain of the 12th Squad, working under Urahara Kisuke, who was the founder of the Department of Research and Development, Hiyori didn't accept Kisuke when he first became a Captain, but if even by a little, she gained little respect for him over time. She was also banished to the real world with all the other Vizard, because they gained hollow powers because of Aizen's hollowfication experiment, and the Gotei 13 thought they gained these powers on their own accord.