|“||It'll be a while before I'm big enough for that though.||”|
–Toshimori, age 4
Toshimori Sumimura (墨村利守, Sumimura Toshimori) is the youngest son of the Sumimura Family and is the only son not pursuing the responsibility of being a Kekkaishi, even though he knows some techniques. He is referred to as Toshi by his family and Tosho by his friends.
Being young, Toshimori is very short. He has short black hair and wears a yellow t-shirt with blue diamonds and shorts around the house.
Toshimori is rather mature and responsible for his young age, which people tend to respond positively to. His friends think he is too serious, his father and grandfather more often trust him (as opposed to Yoshimori) to maintain the house in their absences, and Tokine treats him the way she might a younger brother (though with more patience and warmth than she generally shows Yoshimori). Toshimori is on good terms with his entire family (he and Shuji tend to avoid the regular conflicts between Yoshimori and Shigemori), even his mother despite her long absence in his life. He also shows regular concern for Madarao as a member of the family, not just a tool to hunt Ayakashi. His friends refer to him as "Tosho" (Toshi in the english dub) and often ask him to help them with their assignments, for good reason: Toshimori is an excellent student as well as the librarian of his class.
Though he has at least some potential as a Kekkaishi, Toshimori shows little interest in it and is not at all eager to pursue it. Yoshimori has encouraged him to train, figuring that Toshimori's learned mind will make him a quick study. However, Toshimori recognizes and accepts that while he is capable of reading the family's ancient scrolls on technique, he has great difficulty executing the techniques themselves. Instead, he prefers to stay in the background, supporting his brothers when he can, but otherwise staying out of their way, so as to avoid placing any other burdens on their already stressful lives.
HistoryToshimori was born at some point during his mother's 10 year search for a suitable Shinyuuchi in which to seal Chushinmaru Karasumori. He was only 2 years old when Shigemori first appointed then 7-year old Yoshimori as a Kekkaishi, so he was far too young to appreciate the amount of responsibility involved. Instead of toasting Yoshimori's accomplishment as the others did, Toshimori simply threw the saucer at him, then wandered off once he got bored.
Toshimori's friends Konta and Gatcho guilt him into helping with their homework. They decide to study at Toshimori's house, but he is reluctant, afraid that they'll make a mess. To keep them in line, Toshimori tells them that Yoshimori is really scary. On the way, they run into Tokine, who asks if Toshimori has noticed Yoshimori acting strangely lately. Toshimori hasn't, so Tokine tells him to forget about it. Yoshimori happens to be baking when Toshimori and his friends arrive, which completely ruins the image Toshimori created. Annoyed, Toshimori tells Yoshimori not to bother them while they're studying. However, once Yoshimori learns that Tokine may bring them dinner, he gets excited and creates a cake castle, giving it to Toshimori's friends for a snack. After eating, Konta and Gatcho refuse to keep studying and run through the house over Toshimori's protests. Finally losing his temper, he accidentally knocks them out with a Kekkai. Toshimori is extremely worried, but Yoshimori assures him that they'll be fine, since he and Tokine have been doing the same thing for years. Tokine brings over a pot of curry, but spots a cockroach in the kitchen and freaks out, spilling curry on everyone. Toshimori apologizes to his friends for a bad time, but to his surprise, they had a lot of fun at his house and think Yoshimori is cool.
To make room for the members of the Night Troop that are staying in the Sumimura Home, Toshimori moves into Yoshimori's room. Yoshimori apologizes in advance for waking Toshimori when he leaves at night to go on duty. Toshimori replies that since he can't help Yoshimori fight, the least he can do is not complain over such things. 
Powers and AbilitiesHazama-Ryu Kekkai technique (untrained): Toshimori has been able to sense Ayakashi from a young age, but has little interest in being a Kekkaishi. He is not currently training to be a Kekkaishi, and claims it isn't something he needs to worry about yet. As such, his powers are largely untested: he has produced a Kekkai on two occasions, once accidentally knocking out two annoying friends with a Kekkai spear, and later actually capturing and destroying one of Shion's spider goons. In the second instance, it should be noted that Toshimori was separated from his opponent by a protective layer of charms, and because he was not in any immediate danger, had ample time to focus on his target (though there were many present to choose from). Both he and his father were pleasantly surprised by his success. Toshimori is also capable of producing Shikigami birds, but they tend to crash instead of land.
Low Spiritual Power: Toshimori appears to have very little spiritual power, though he is still able to sense supernatural beings and events (which implies that he still has more power than his father, who is unable to see most Ayakashi).
- Main article: Yoshimori Sumimura
While they generally get along well, Toshimori is sometimes embarrassed by Yoshimori's immature behavior, and wishes he would act more his age. One of the few areas where Toshimori admires Yoshimori is in Kekkaijutsu: because he does not practice himself and has considerable difficulty with the techniques, Toshimori is easily impressed by his brother's natural talent. On the other hand, Yoshimori is impressed that Toshimori can understand the ancient family scrolls, and the two sometimes end up encouraging each other while facing their own self-doubt.
- Main article: Masamori Sumimura
Toshimori greatly enjoys spending time with Masamori, and they usually play board games together while Masamori is at home.
- Main article: Tokine Yukimura
Despite the feud between their families, Toshimori and Tokine are quite comfortable with each other. Toshimori views Tokine as an older sister, and Tokine is notably kinder to Toshimori than nearly any other Sumimura. In addition, because they are each more familiar with a different side of Yoshimori, they exchange information to ensure that Yoshimori isn't doing anything too reckless or dangerous.
Taichi Komagome & Gaku Mikawajima
Taichi and Gaku are Toshimori's friends and classmates. They seem to like Toshimori chiefly because he is smarter than them and can help them with their homework, a fact that Toshimori is careful not to let them exploit too often. Toshimori is easily annoyed by their unwillingness to work and constant desire to goof off, but likes them despite this.
- Toshimori shares a notable personality complex with his brothers: they each see themselves as being unfit for their position in the family. Yoshimori takes Toshimori's being able the read the ancient family scrolls as proof that he is more fit to be a Kekkaishi, but Toshimori disagrees because he has little talent for the techniques.
|First Kekkaishi||Tokimori Hazama|
|Legitimate Successors||Yoshimori Sumimura • Shigemori Sumimura|
|Other Kekkaishi||Masamori Sumimura • Sumiko Sumimura • Toshimori Sumimura|
|Legitimate Successors||Tokine Yukimura • Tokiko Yukimura|
|Other Kekkaishi||Tokio Yukimura|
|Kekkaishi||Yoshimori Sumimura • Shigemori Sumimura • Sumiko Sumimura • Masamori Sumimura • Toshimori Sumimura|
|Ayakashi||Madarao • Shimano|
|Normal Human||Shuji Sumimura|