Kosuzu Motoori

Kosuzu has a sweet personality, considerate and optimistic, polite and cheerful with her customers and her friends, and enjoys telling stories to village children. However, she is very confident in herself and her abilities, which frequently gets her into trouble. She thinks she knows better than most other people, distrusting Reimu and often taking matters into her own hands, with disastrous consequences (as when she tried to summon a smoke youkai to deal with a word worm [2]). She's highly curious, and often dangerously so, being unafraid to read and make use of the Demon books she owns, even after learning that they contain the power of youkai, and goes to many different measures to acquire information.

Despite this confidence, she can be quite cowardly as well. She develops a temporary fear of snakes after hearing a rumor that they can eat a human whole, and gets worked up over a horror story she hears from a pair of children, even after dismissing it as illogical. She's also prone to fainting when startled, whether it be in a dangerous situation or even if it's actually something benign. [3] It is said that she didn't enter in panic after knowing Mamizou Futatsuiwa was a youkai just because she read Akyuu's books about youkai infiltrating in human society. [4]

Kosuzu is very conflicted over how she should feel about youkai. While Hieda no Akyuu, her good friend, and Reimu warn her that youkai are not to be trusted, she is on good terms with Aya Shameimaru and Mamizou Futatsuiwa, both of whom she is aware are youkai, and have never attempted to hurt her. She wants a definite answer over whether or not youkai are her friends or foes, and wants to understand her purpose in Gensokyo, but the conflicting opinions of her various friends cause her great frustration, and she struggles to form her own. As a result, she became possessed by the Night Parade of One Hundred Demons scroll.

Family
Kosuzu is known to have a family. On several occasions, she'd talk or yell to her parents in the shop, but they were always off-panel. One example is the beginning of chapter 13 where she asks her mother if she knew where her shoes were. She also made reference to her grandfather, in which he was the one who taught Kosuzu about the "word-eating worm", but it's unknown if he's still alive.

Mamizou Futatsuiwa
A regular patron of the store in her human disguise, Mamizou Futatsuiwa speaks to Kosuzu in a friendly manner and offers her advice on supernatural matters. While Reimu frequently warns Kosuzu of the dangers of interacting with youkai artifacts, Mamizou has no such compunctions and merely advises her to keep her hobbies secret so that people like Reimu won't take her books away. Unaware of Mamizou's true nature for most of the story, Kosuzu looks up to her as a role model, seemingly trusting her more than any other adult.

Hieda no Akyuu
Due to their shared interest in books, Kosuzu and Hieda no Akyuu appear to be close friends - Akyuu frequently visits Suzunaan to borrow books, both from the Outside World [10] and youma books [11] and the two speak far more casually when in each other's company. Akyuu is aware that Kosuzu's continued dabbling in demon books could potentially turn her into a youkai, but does not actively try to stop her, only warning Kosuzu that becoming a youkai would make her life difficult. She also tries to keep Kosuzu in the humans' path telling her, in a way Kosuzu finds annoying, that youkai are still their enemies and that that's the truth more beneficial for them.

Kosuzu is a young girl with red eyes, ginger hair and twintails adorned with bells. She wears a checkered kimono and apron with Kosuzu and 鈴奈庵 (Suzunaan) written on the front. She uses glasses to read. When she goes outdoors she'll wear a coat.

Kosuzu is a part-timer that works at Suzunaan, a library specializing in books that appeared in Gensokyo from the outside world. She lends books to various characters throughout her manga. After the events of Forbidden Scrollery, she began to lend demon books too from time to time. She also does printing work, as it is one of the services offered by Suzunaan.

Appearance

Seija is a small, youthful-looking girl with short black hair and striking red eyes. She often wears a dark-colored outfit with a black hat decorated by a red ribbon. Her design has a somewhat impish appearance, combining a cute look with an expression that suggests she’s constantly plotting something. She is frequently associated with upside-down imagery and unusual poses, giving her a visually unconventional and rebellious feel.

Personality

Seija is contrarian to an extreme degree. She dislikes following rules, social expectations, or common morality simply because they are accepted by others. If a crowd supports something, she is inclined to oppose it. If people consider an action wrong, she may find it appealing specifically because of that.

She enjoys provoking reactions, stirring up trouble, and challenging authority. Manipulative, cunning, and opportunistic, she often acts in ways that benefit herself while creating chaos for everyone else. She tends to be distrustful of others and is not particularly concerned with loyalty or cooperation.

Despite her antagonistic behavior, she is not driven by a grand ideology or a desire for destruction. Much of what she does comes from a deep-seated urge to reject the status quo and turn established ideas on their head. This makes her unpredictable; she can be clever, funny, irritating, and dangerous all at once.

In short, she is a mischievous rebel whose defining trait is opposing things simply because they are accepted.

Kosuzu seems to know and respect Reimu very well, speaking to her in a friendly and polite manner. However, she has heard the rumours of the Hakurei Shrine being infested by youkai and it sometimes colours how she interprets Reimu's actions. Reimu addresses Kosuzu as "Kosuzu-chan".

Kosuzu holds a great deal of respect and admiration for Reimu. In one instance, she even expresses belief that no harm will come to her from dealing with youma books because Reimu will surely come to her rescue if anything happens. Reimu, on the other hand, views Kosuzu with a mix of affection and irritation. As the primary protector of Gensokyo, she is often placed in the position of having to clean up the messes that result from Kosuzu's obsession with youkai and their books.

A key point of tension is Reimu's duty as a shrine maiden to exterminate youkai, a job that is constantly challenged by Kosuzu's growing sympathy and dealings with them. During a major incident involving Kosuzu and a night parade scroll, Reimu is revealed to be secretly glad that the powerful youkai Yukari Yakumo is behind the issue. This meant she didn't have to fight someone close to Kosuzu, which shows how much she cares for Kosuzu.

In another example, Marisa Kirisame, Reimu's closest friend, teases Reimu for being soft on Kosuzu. When Reimu decides to simply reseal a vengeful spirit possessing Kosuzu's goods instead of exterminating it, Marisa calls her a "liar," implying Reimu was being lenient because of her feelings for Kosuzu. After Kosuzu is saved from being absorbed by a cursed scroll and temporarily loses her memory of the incident, Reimu chooses to tell her the truth about youkai. She does this even over the objections of others, like Marisa, showing that she now trusts Kosuzu with the full scope of reality, including the dangers.

As a frequent customer of Suzunaan's and a fellow collector, Kosuzu and Marisa are on friendly terms. Like Kosuzu, Marisa is also an avid collector and researcher of magic books, though she has a reputation for "borrowing" them without permission. A key difference is their attitude toward the dangers of youma books. Kosuzu is often naïve about the harm these books can cause and is more concerned with their rarity than their potential to attract youkai. In contrast, Marisa is aware of the risks but, as a magician and youkai exterminator, she embraces danger and recklessness to further her own magical knowledge.

In one notable chapter, Reimu and Marisa confront Kosuzu after she is possessed by a vengeful spirit attracted to some youma books. When Reimu decides to simply reseal the spirit instead of exterminating it, Marisa calls her a "liar," accusing Reimu of being soft on Kosuzu because she feels guilty for having hurt her in a prior incident. Marisa's insight and teasing imply she understands Reimu's concern for Kosuzu on a deeper level.

In the same incident, Marisa's focus is on resolving the danger quickly and decisively, while Kosuzu pleads to save the books, demonstrating her misplaced sense of value. This highlights the difference in their perspectives and priorities. As Kosuzu's fascination with youma books deepens, Marisa joins Reimu and the others in keeping the village girl in the dark about the deeper mysteries of Gensokyo. This is done out of a belief that revealing too much might put Kosuzu in greater danger. Marisa's involvement shows that she, like Reimu, understands the line between Gensokyo's human and youkai worlds.

After the final incident involving the cursed scroll, Reimu decides to come clean and tell Kosuzu the truth about youkai. Marisa's presence during this event, and her previous interactions with Kosuzu, imply that they now share a relationship built on a more honest, though still cautious, understanding.

Kosuzu and Aya have become business partners in the selling of the Bunbunmaru Newspaper for the Human Village. Aya, a cunning journalist, sees Kosuzu as a source of information and a business partner, while Kosuzu, initially naive, gradually becomes a more willing participant in Aya's dealings. Aya regularly distributes her tabloid-like newspaper, the Bunbunmaru News, through Kosuzu's shop. For Aya, this is a way to spread her influence in the Human Village, a hub she and other tengu want to control.

While the arrangement primarily benefits Aya, it also grants Kosuzu a deeper connection to the youkai world she is so fascinated by. The newspaper provides her with a different perspective on the incidents and residents of Gensokyo, which feeds her curiosity about youkai. Aya views Kosuzu's book-deciphering ability as a valuable resource. When a special news story breaks out, Aya immediately seeks out Kosuzu for information, as she knows Kosuzu is the only human who can decipher the youma books.

Kosuzu claims to have the largest collection of demon books in all of Gensokyo stored in the library she works at. It's essentially her pet project and hobby

The ability to decipher books by only touching them

Gensoyko. An Isolated society away from the human world. She resides in the Human village.

Kosuzu Motoori

Human