Kagami Kasumi (加賀見霞, Kagami Kasumi) is the elder sister of Kazuya Kagami, as well as the daughter of Kanaka Kagami and Kazuaki Kagami. With their mother gone and their father working all day, Kasumi has taken responsibility for most of the household work while watching over her brother.
Kasumi is a young woman with a long straight black hair. Beyond their different hair she closely resembles her mother on her younger days, both in facial traits and in physique. Her attire is typically casual and simple.
Kasumi's only two years older than her brother, but she is mature and very independent, taking care of most of the house's affairs on her own, and comes off as a very reliable person despite her age. She is notorious for her "brother complex", and is suggested on more than occassion that she has a romantic obsession for her younger brother Kazuya. She's constantly attending to any necessities he may have on the daily life, like cooking for him or waking him up on the mornings for school, coming off as closer to a mother than a sister. She's constantly watching over him and making sure that he doesn't go through any misfortunes, but she's also extremely obsessed with him and doesn't want to be separated from him. She's also shamelessly open about her incestuous obsession, often trying to get more intimate with him or pushing him to bath together, and she's been described by Kiriha as a "brother-holic". She's been like this since they were little, and she used to sleep and bath with him until he got old enough to refuse his sister's company, which greatly distressed Kasumi as she felt that he was entering in a "rebellious phase". She's quite a pervert, as even from a young age she was "teaching" an innocent Kazuya about matters related to sexuality that were inappropriate for a boy of his age.
She does not get along well with Kiriha, as she dislikes her self-centered nature and often tries to make her do some housework. Fortunately for her, she's much better than her relatives at dealing with the Tsugumomo, and is the only one on the house that can keep her under control. She's diligent and works hard to cultivate an image as a dependable figure, so she does not mind the work it takes. She's very protective as well, quickly rushing to her brother's room whenever she hears a suspicious noise, especially if she believes Kazuya could be in danger. She was originally against the idea of accepting Kukuri and Kokuyou on their house, but she ended up being way more fond of Kukuri than she is of Kiriha.
Kasumi was born from the union between Kanaka Kagami and Kazuaki Kagami, two years prior to the birth of her brother. When she was 6 years old Kanaka was planning on making one of them her successor and Kasumi, who had never showed any enthusiasm in becoming an Exorcist, willingly accepted the role in order to protect Kazuya from her mother's rigorous training and the dangerous life of an Exorcist. While she was very talented, Kanaka was not quite satisfied with her performance, as she was looking for someone that would be able to match or perhaps even surpass her. However, Kazuya eventually showed a potential comparable to Kanaka's, leading to him being recruited for the training as well and making Kasumi's efforts worthless. In a period of only three years, Kasumi was no match for her brother and failed to keep up with their training.
Following the event the event where Kazuya's memories were sealed after their mother was possessed by an Amasogi, Kukuri told her and Kazuaki everything about the incident. Filled with a desire to protect her brother, she secretly continued training without telling Kazuya. She was quickly recognised for her great ability and was gifted with the Hourglass Tsukumogami Saori, who became her partner when she was appointed as an Exorcist.
Befitting Kanaka's daughter, Kasumi was called a prodigy child since a young age and was described as being a talent seen only once per generation. She was personally trained by her mother for some years, resulting in her developing a considerable amount of fighting ability. She's quite skilled at martial arts and is physically strong, capable of fighting Amasogis even bare-handed. Despite her impressive potential, she was never quite on the same level as her brother and mother, and would quickly fall behind to Kazuya's much faster progress.After becoming the owner of the Hourglass Tsugumomo Saori, she began training to use her to its full potential and earned access to her powerful and unique abilities:
- Time Manipulation: With Saori's special powers, Kasumi is able to manipulating time at will, typically to make it run faster, slower or even stop it. However, Saori can only control time in what she calls an "Area of Effect" and everyone inside that area is affected equally by her powers. While this limits her potential uses, she's still capable of utilizing in a designated area where it only affects a single person or object, like slowing down enemies attacks or increasing Kasumi's own time to react to see through their opponent. As incredibly useful as this ability is, it comes with the drawback of having a time cost, which forces the user to sacrifice an equal amount of time of their own in exchange.
- Time Stopping Barrier: An advanced technique developed by Kasumi. By surrounding a specific area in circles, Kasumi and Saori are able to create a barrier that freezes the time inside for a determined period. At its greatest potential, Kasumi is able to make the time freezing barrier last as many as three years. This move was powerful enough to restrain even Kanaka Kagami, as it is impossible to escape from its effects once trapped inside. However, it has the rather huge drawback of trapping the user and Tsugumomo Saori as well.
- When Kazuya was hypnotized by Osamu Osanai to reveal his unconscious desires, he burst out expressing all his repressed sexual repressions from living with many beautiful women. Notably Kasumi was the only one he didn't express lust for.