|Grade||2nd Year Junior High school student|
|Favorite Food||Udon and Dried Sardines|
|Japanese Voice||Juri Nagatsuma|
|English Voice||Sarah Anne Williams|
Karin has brown hair, tied into two pigtails held by red and black ribbons. She has olive-green eyes. At school, she wears the standard school uniform with knee-length grey socks and black shoes.
In her hero form, her black and red ribbons are replaced with red, flower-shaped bows. Her outfit consists of a red, white and black dress with white lines and flower patterns on it, and black shorts underneath. She has a red flower pin on the left side of her chest and a pair of ribbons hang from the same shoulder in both the front and back. She has long, thigh-high boots that has a red and black gradient on it. Her gloves fade are a black and red gradient with white straps and lines. Her Mankai gauge, which resembles a Laurel flower, is located on her left shoulder.
Karin was assigned to the Sanshu Middle School Hero Club by the Taisha in order to oversee their activities. She was not originally selected to be a Hero, but as a result of ruthless self-imposed training she was deemed fit to become a Hero by the Taisha. Thus, the Hero terminal that originally belonged to Minowa Gin was modified and given to her. Although Karin's family is still alive, she lives alone in an apartment complex.
In the second visual novel, Karin revealed that the reason she trained to become a Hero was because she constantly felt inferior to her older brother, who has a high position in the Taisha.
Karin is depicted as a headstrong individual: stubborn, obstinate, and single-minded. She is very abrasive and finds it difficult when expressing her feelings towards others, resulting in her becoming distant towards her fellow companions. Her years of constant training have left her no time for making friends, and she claims to have never celebrated her birthday in her life. As a result, she is physically active and very intelligent, having scored near-perfect scores on her entrance exam. In terms of her abilities as a guardian of the Taisha, Karin is revealed to be very self-confident and positive, initially believing her skills are far greater than the other members of the Hero Club. During her first encounter with the Hero Club, Karin is quite repulsive and irritated by their carefree and optimistic behavior, viewing the four of them as unworthy of being Hero's. However, despite being a highly skilled and capable guardian of the Taisha, Karin, being the only Hero out of the five to not turn Mankai during battle, she begins to feel incapable and unprofitable of the Hero club, blaming herself for not being able to protect the other members. Although Karin often lashes out at people who act friendly toward her, such as Yuna, she is eventually revealed to be a kind, lonely girl with an inferiority complex. She ultimately comes to care deeply about her new found friends, and, over the course of the series learns to be honest with her feelings. Karin ultimately becomes very close with the members of the Hero Club.
Additionally, Karin can be described as a "Tsundere", meaning she is initially viewed as hostile and unfriendly, but in truth is actually isolated and imprecise. Although she desires to have companions, Karin, over the course of the series, continues to struggle whether or not she is supposed to be accompanied or cherished by others, viewing her only reason of living is to serve the Taisha. After joining the Hero Club, Karin realizes that she should be in full view of the Hero Club, but struggles to open up to them. This might be the result of feelings inferior of her older brother, who supposedly has more potential than her due to his high position of the Taisha. Outwardly, Karin strongly respects the Taisha, having trained for many years. Even when Fu explains to Karin that the Taisha used her along with the other members of the Hero Club as sacrifice, she refuses to believe it. Overall, Karin's character is highly expanded throughout the series. Thanks to the kindness of Yuna and the others, she slowly becomes more open to the Hero Club, and desires to protect the four of them at all costs. She also learns how to fight alongside them, and realizes that despite their rather insouciant temperaments, they have just the same amount of potential of being a Hero as she does, and later widely accepts that fact. Karin may continue to lash out at them on occasion, but deeply regards of them.
- Yoshiteru: (義輝) A shogun spirit clad in red armor with two blades sheathed on his back. Yoshiteru is capable of speech unlike the other fairies, although it seems to be rather limited. He tends to say "Shougyo mujou" (All things must pass), usually in comedic situations.
Karin's fairy, Yoshiteru, grants Karin twin katana which she dual-wields. Karin is also able to throw her katana to strike at range, while being able to generate new ones. Karin also has powerful physical abilities, and can sense things without being able to see them.
Karin's Mankai form takes the form of four giant, mechanical arms, each holding a large version of her katana. In addition to slashing with them, her Mankai can also fire a rain of katanas as well as unleash a sword beam. However, despite her Mankai's great power it seems to be very fragile, dissipating after taking only a single hit. It is probable that her Mankai is so fragile because of its overwhelming strength as she is able to destroy a Vertex with a single strike. Due to using Mankai multiple times in Episode 11, Karin loses faculty of her right arm and leg, as well as both of her eyes and her ears.
Karin's classmate and fellow club member. Karin was antagonistic toward Yuna's friendly nature when they first met, but the Hero Club's persistence caused her to slowly open up to her. She comes to care about Yuna deeply and eventually tells her that she doesn't want to see her cry. After her fight and losing faculty of much of her body as a result, she thanks Yuna for showing her what friendship is. She can also be called a tsundere towards her friends.
Karin's classmate and fellow club member. Although Karin started off rather antagonistic toward the Hero Club, Karin feels that Togo is the one person whom she can't bully. Togo's intense and strange behavior is often at Karin's expense, such as during her punishment game in Memories of the Forest. In time the two girls become friends, and in the second visual novel both are united in outrage when Yuna receives an anonymous love letter. Despite Karin having suffered much due to Togo's attempt to destroy the world, Karin is more worried about her and Yuna than herself during their recovery.
Karin's senior and club president. Karin initially doesn't respect Fu as a leader and openly states that she would be able to lead the club better. Karin's stubbornness and Fu's immaturity often make them butt heads, but they eventually grow to care about each other deeply and develop a friendly rivalry. Karin checks up on Fu when the Taisha warn her that she is mentally unstable, which leads to their fight in Episode 9. However, they don't hold it against each other afterward.
Karin's junior and fellow club member. Unlike the rest of the Hero Club, Karin doesn't seem to be initially annoyed by Itsuki, and even openly helps her to pass her music exam. Supplementary material often shows them bonding over them both being little sisters. Later on, Karin reveals that she would like to have Itsuki as a little sister.
- Karin's flower appears to be Rhododendron indicum, or Evergreen Azalea.
- Karin was not in the initial drafts of the plot; rather, she was added in toward the end of preproduction to act as a foil to the other girls, using the personality traits that the other girls didn't have.
- Karin's fairy, Yoshiteru, is likely named after Ashikaga Yoshiteru, the 13th shogun of the Ashikaga shogunate who reigned from 1546-1565. Ashikaga Yoshiteru was a shogun who was well known for his skill with the katana, to the point of being called the "Kengo Shogun", but was eventually undone by the Miyoshi clan.