Black★Rock Shooter (OVA)
Mato is a black-haired school girl with blue eyes. She has short, choppy pig tails and wears a seifuku consisting of a white top with a dark blue collar and a dark blue skirt. She wears black knee-high socks.
She has a patch of bandage on her right knee, after getting an injury from basketball practice. Many of her belongings, including her clothes, phone charm, and room decorations, have a star motif.
She is described as being 155cm tall, while her "other self", Black★Rock Shooter, is about 156-161cm.
Black★Rock Shooter (Anime)
Mato retains most of her appearance from the OVA, aside from wearing a different, non-seifuku school uniform. She wears a white shirt and a yellow almamater on it. She also wears a ribbon tie. Different from the OVA, she wears a pair of white socks and brown shoes. The patch of bandage on her right knee is gone, though she now has a bandaid on her right thigh.
Black★Rock Shooter (OVA)
She is an innocent and naive first year student in middle school. Outwardly, she is outgoing and excitable, but she is very awkward around people she does not know. Internally, she is a sensitive and meek person, but eventually learns to gain courage.
Black★Rock Shooter (Anime)
She is fond of philosophical musings, and often will mutter about the world around her to no one in particular. Saya describes her as the kind of person who has, until now, never hated anyone or had anyone hate her.
Her favorite food is curry.
She is very fond of the book Li'l Bird Li'l Bird Colorful Colors and reads it repeatedly.
Black★Rock Shooter (OVA)
In her first year of junior high school, Mato comes upon Takanashi Yomi when looking for friends to make and decides to strike a conversation with her. Mato's bluntness and outward personality shocks Yomi initially, but the two become friends eventually. They begin to turn to each other for everything, and Mato eventually shows Yomi a special place which is known as the Meeting Place where one can see a large view, and gives Yomi a cell phone charm with a star (identical to the one she has herself). Additionally, Mato's skill in basketball encourages Yomi to join the volleyball team.
Things change in her second year. The two are put in separate classes, and Mato finds and befriends the basketball team's manager Yuu from her class. Mato initially tries to get both Yuu and Yomi to be together with her at the same time, but ends up spending more time with Yuu. This makes Yomi feel "left out" and causes the rift to increase.
Mato starts to worry about Yomi, but things get serious when Yomi suddenly vanishes, not responding to any calls or texts. Initially Mato believes this means Yomi is avoiding her, but when two men come to her house asking about Yomi's disappearance, Mato breaks into tears and continues halfheartedly searching for Yomi.
Eventually, Mato gets a mysterious text from Yomi with nothing in it. Convinced that this is a clue, Mato runs out of her house (wearing a black jacket with a white star on the back) and rides her bike up to the place she showed Yomi. She finds the phone charm she bought for Yomi and holds it to her chest, finally realizing what Yomi means to her.
A light erupts from the charm and envelops her, transporting her to a strange place filled with light. She meets Black★Rock Shooter there, and reconciles with her "other self," who offers to help Yomi. The two merge and both identify herself as Black★Rock Shooter, allowing both to save Yomi.
In the end, a reconciled Mato and Yomi walk home from school; however, Mato remains unaware that Yuu is in a dark state...
Black★Rock Shooter (Anime)
Mato arrives at school on the first day. While in zoning out, she trips and falls. Yomi helps her up. She sees the bracelet on Yomi's wrist, and comments on it.
Mato looks at her class roster and notes that the girl's name is read as "little birds playing". Still confused, she walks home with her childhood friend Yuu, discussing this strange person whom she is determined to make friends with.
As she goes home, she muses about her favorite book, Li'l Bird Li'l Bird Colorful Colors, a book about a small white bird that takes people to worlds of different colors.
The next day, she meets with Yomi, and learns her name "Takanashi". She asks Yomi if she is interested in any clubs, but Yomi avoids the question and quickly leaves the room. She later meets Saya Irino, who advises her to drop by should any problems arise.
Mato joins the basketball club shortly after; Yomi sees running, and thinks of her calling as "beautiful".
Yomi later notes that Mato has a phone charm for The Tiny Bird and the Colors, a book she also has, and shows her the cell phone screen saver of the cover of the first edition. She invites Mato to her house. She gives Mato her bracelet as a present. However, they run into Kagari Izuriha, who insults her and drives her away. Mato leaves and runs home in tears, terified by the experience. She then receives an apologetic text from Yomi.
Mato visits Saya the next day and confides that she's afraid of Kagari. Saya tells her that she will inevitably make enemies, and that there is always someone bearing her pain for her. With newfound determination, Mato visits Yomi in the art room. Yomi protests that Mato cannot be friends with her because it would only get her hurt. Mato refutes her, and insists they should go to the local festival together.
Yomi, however, does not show up at the festival. Mato receives three text messages from her: "I'm sorry". Mato runs back home, hurt at Yomi's "lie".
The next morning, Mato finds Yomi in the locker room and notices that she has the same heart-shaped scar on her chest. She questions it, but Yomi hides it and asks Mato why she isn't angry about Yomi not coming to the festival. Mato says that if she wants her to be angry, she will be. Mato states that Yomi is not, like her name implies, a little bird; she has the potential to go to many different worlds, but refuses to do so.
She goes to Saya's Counseling room along with Yuu, and tells them about her dream. Saya tells her that a dream might be a way of conveying things that can't be said in words between close friends. With this in mind, Mato returns to Yomi's house. However, she hears Yomi screaming and a commotion. Mato bangs on the door just as Yomi's mother comes home.
At the hospital Mato is told that, depite only spraining her wrist, Kagari claims to be unable to use her arms anymore, and demands that Yomi's full attention and care. Yomi's mother tells Mato about how Kagari ended up getting hit by a car when trying to chase Yomi when they were children; despite the incident, Kagari is not physically harmed. Mato protests. She says Yomi shouldn't be tied to Kagari. Yomi's mother agrees, but pities Kagari and thus allows the situation to continue as is.
Mato bangs on the door to Kagari's room, demanding Yomi to come out. Mato tells her that Kagari is only pitiful because Yomi enabling her. Yomi gains the courage to confront Kagari and tries to snap her out of her sheltered life. In the meantime, Black★Rock Shooter beheads Chariot. Yomi opens the door. Mato finds a cheerful Kagari inside who then falls over asleep. The next day, she and Yomi discuss Kagari's situation. Mato learns that Kagari has become calmer and is now taking walking exercises.
Mato runs into Yuu who rushes her to a meeting. At the basketball club's gathering, captain Arata Kohata deems her suitable for becoming a semi-regular in the basketball tournament, and tells her she must go through training. Mato is made nervous as Arata tends to be rather strict.
As Mato washes her face with Yuu they accidentaly peep on Arata giving a love letter to a boy. She catches sight of the duo and they run for it.
As Mato prepares for her training, she muses about the girl she saw in her dream, and wonders if she is like the bird that absorbed the colors of many worlds into its wings. Yomi calls Mato for small talk. As Mato mentions Yuu quite a bit, Yomi grows uncomfortable, and quickly ends the call.
Mato goes on the sports training trip. There, she goes through harsh training. The other girls question whether she can fill in the team's niche and become a semi-regular, but Arata has confidence in her.
That night, Mato dreams of Black★Gold Saw raising strange figures like plants with a watering can. She is wakened by the shock. Mato confides in Yuu about her dreams; Yuu wonders if these people bear Mato's pain for her.
The sports team goes souvenir shopping. Mato and Yuu see Arata buying a wooden sword for the boy she likes. Yuu asks Mato if she wants a boyfriend yet. Mato answers that it's too soon to think about that, but Yuu comments that she already has her "Tiny Bird," referring to Yomi.
Upon their return, Mato gives a box of sweets to Yomi as a gift. Yomi in turn gives her a blue bracelet she made. However, as Mato talks about the trip, and consequently, about Yuu, Yomi becomes visibly uncomfortable. Yomi laments that she isn't Mato's best friend.
They come across a crowd of students; Arata's love letter had been taped to the bulletin board for everyone to see. They watch on as Arata is made fun of by the other boys. Arata laughs it off and walks away. Mato, Yomi, and Yuu go elsewhereto mull about their situation. Mato and Yuu begin to cry, thinking about Arata covering up all her pain.
In basketball practice, Arata trips over and twists her ankle. Mato escorts her to the infirmary,and decides to go get a teacher, though Arata is resistant to getting help from Saya. In the other world, Black★Rock Shooter beheads Arata's other self. Mato senses it. she runs back to the infirmary to find Arata prone on the floor.
Kagari returns to school the next day, and Mato watches as she quickly becomes popular with the other girls. Yuu tells her that Arata has recovered. She is put in charge of the basketball team, since Arata is now unable to participate in the preliminaries.
As a result, Mato cannot walk home with Yomi anymore. Yomi is unnerved, especially at the mention of Yuu.
Mato attempts to meet with Yomi the next day, but finds Kagari instead. They walk to school together and come across Yomi, who gets upset with Kagari because she had been waiting for her.
After basketball practice, Kagari asks Mato what she should give to Yomi as a present, as she wants to repay Yomi for all she has done for her.
Mato tells Kagari that she should give Yomi something that she made at the cooking club she recently joined. The two run into Yomi, who denies being upset about Kagari having other friends. Yomi runs away once she sees Kagari and Mato together.
She goes into Saya's counseling room to ask for advice, however Saya tries to choke her. She runs away and goes into the art room. She finds a crowd looking at the picture painted by Yomi that depicts a bloody Mato crying with a star on her left eye. A student asks if she can take the picture away.
Mato looks for Yuu. However, she gradually starts forgetting her face and the memories they had together. She looks for her house. In it's place, she comes across a river bank.
Mato finds Yuu who tells her her about the other world. Yuu asks if Mato wants to save Yomi. She answers yes. Yuu transports Mato to the other world where she fuses with Black Rock Shooter. She is forced to look as Black Rock Shooter kills Dead Master. Mato enters a shock that turns Black Rock Shooter into Insane Black Rock Shooter.
- Mato's surname is sometimes misread as "Kokui" due to the fact that it would be the more common pronunciation of the kanji in normal wording: however, "Kuroi" as a surname is the proper pronunciation.
- The kanji for her surname means black clothes. "Mato," with certain kanji, can mean target (as in target shooting).
- Her father is not mentioned in the OVA. In the anime Mato's mother says that her father is always going in a business trip, though Mato doesn't feel alone for it because she pretends to be an adult and understand that her father has to work for the good of his family.
- The name 黒衣マト (Kuroi Mato) is pronounced the same with 黒い魔都 (Black Devil's Castle).
- Mato entered Saimoe Contest.