Yuzuriha wields a sword from a spirit dog, Inugami. But then her name is different from it. Yuzuriha's last name, Nekoi is composed of the kanji 猫 which means 'cat' and 依 which means 'dependent'. While her name Yuzuriha is composed of the kanji 護 which means 'protection' and 刃 which means 'blade' or 'teeth', just as her Inugami transforms as a shield and sword.
Yuzuriha appears as a genko girl from the Mitsumine Shrine, a super hyper and childish one. She first appears in front of the other characters in the Diet Building. Yuzuriha is the smallest among the Seals and indeed a little bit smaller than Kamui. She has really a short black hair and dark blue eyes. In the anime she mostly wears a uniform, a green and white blouse with a big red ribbon and a short skirt with a pair of white socks and black shoes. While in the manga, she also wears as black dress uniform with white collar and ribbon.
Yuzuriha is a cry baby not to say that she is the youngest among the Seals. She has a strong willed-personality. Even with her younger age, she is very optimistic. She is also hyper and friendly just as Sorata does. If Kamui is like Arashi when it times to personality, Yuzuriha and Sorata are identical in personality.
Yuzuriha first appears as a girl from the Mitsumine shrine that is excited about going to Tokyo and meet up Kamui. She don't want to date anyone around that doesn't see Inuki until she meets Kusangi that does. Right away, she meets up Hinoto, Saiki, Sorata, Arashi and Kamui in the Diet Building with the help of Inuki. But then, Sakurazukamori interrupts their conversation because he is drawn from Yuzuriha's finding to Hinoto by a Spirit Dog. Inside the illusion, she was able to transform her dog to a sword. In the end, Kamui becomes strict to Yuzuriha like he does to others that got involve with him. She even offered Kamui a snack to relax and refrain himself but it has a different result. In that night, Yuzuriha and Inuki followed Kamui in the Tokyo tower, watching him alone.
Her next appearance is with Saiki on their way to find Aoki on Yasukuni Shrine. Yuzuriha offers an ice cream and as Saiki waits for her, Yuzuriha was on her way to buy when she founds Kusanagi on the park and met him again. Yuzuriha told Kusanagi why she was so glad when he just met Inuki. Yuzuriha told Kusanagi that when she was a child, everyone thinks that she is a liar because of Inuki until the time that she realize that she should stop talking about it. Until Yuzuriha become mislead of the time and let Saiki wait too long until she don't bought any ice cream. But Aoki offered them to a restaurant that sells ice cream and learns that Saiki is Aoki's nephew.
On the anime, when the three of them realize an appearance of the first Dragon of Earth on CLAMP campus they reacted with it but they weren't able to catch up with Kotori's murder. But in the manga, along with the other Seals except Karen and including Saiki, they were present with the said event. When Kamui falls on a catatonic state, all she could do is too cry because of the sudden climax of events and Arashi is confronting her all the time. After that, she becomes attached with the younger Seals (particularly Sorata, Arashi, Kamui and Subaru).
One time, she had face a battle against Satsuki and her Cyber, 'The Beast'. During the fight, Yuzuriha had to face a difficult question from Satsuki, 'Why does killing humans wrong?'. In the end, she wasn't able to answer it until then, Inuki dies in protecting her. And because of that, her barrier field broke apart. Luckily, Kusanagi manage to save her before the place turns into ruins. When she wakes up, she founds Kusanagi right by her side and found herself in one of the camps of Japan's Self Defense Force. Yuzuriha told Kusanagi that Inuki saves her life and dies because she can't answer the question but Kusanagi told her that she knows the answer because she cries about the lives that are lost and also because of the death of Inuki.
Kusanagi realize that Yuzuriha is one of the Seven Seals. And the other seals are still searching for Yuzuriha. Yuzuriha told Kusanagi that she likes him and she hopes that it will not be a burden if she loves him. As she made her way back to the others, she told herself that she should live for the life that Inuki saves and encounter the Kamui of the Dragons of Earth. But luckily, she was saved by Kamui. When Kamui and Fuuma fights and she notice that Kamui is already near to lose from Fuuma by death, she tolds herself that she wants to protect everyone and a new puppy appears between the two and avoids them to fight. Yuzuriha named him as Inuki as well. Kamui and Yuzuriha leaves and arrive at the Diet Building wherein Inuki notice the change about Hinoto. With the other seals, they went to Yasukuni shrine and remembers the time that she is with Saiki there when they are waiting for Aoki.
Like the others, she wasn't able to realize the change that happened at Hinoto and when Subaru leaves, she and Arashi was assigned to protect Inokashira Park and told Arashi that she thinks that Arashi is in love with Sorata because of her look when Kamui and Sorata leaves to protect Ginza. In the manga, she is along with Kamui, Aoki, and Karen in the final battle and told Kamui that even for a moment, that for them, he is still the Kamui-san they have come to know before being the real 'Kamui'.
In the anime, she was saved by Kusanagi while fighting Nataku and along with the others that saw Kamui's barrier field. In the epilogue, she is with Kusanagi in the waterfall that she and Inuki once visit when she was still a child.
In the movie, she was killed not so long after Kusanagi is killed. She is with Kamui when they encounter Kusanagi in one of the shops of Ebisu. Unlike the manga and anime, there was no connection between the two and Kusanagi was more dedicated to his role as one of the Dragons of Earth
Kamui and Yuzuriha are one of the youngest members of the seal that made their relationship deeper like any others. They are contrast in their personality but they are commonly seen to be alone and lonely with the tragic of their childhood.
Yuzuriha is really a kind and innocent girl that's why sometimes, when the seals' job is to protect Kamui's safety the other way happens, they come for Yuzuriha's very own safety being the youngest among the Seals.