Natsume

Natsume Takashi is a frail-looking but surprisingly resilient sixteen-year-old boy. There's nothing flashy about his appearance, but his gentle, slightly melancholy refinement immediately draws attention.
Appearance and features: He has light, wheat-blond hair with soft, casual bangs and an elongated, pale face. His most striking feature is his eyes: golden-brown, amber, with a slanted, fox-like slant. They often convey a quiet thoughtfulness, caution, and a deep sensitivity to the world around him.
Clothing: Natsume prefers simple, understated clothing—the standard school uniform or casual light-colored shirts, simple sweaters, and trousers. He has no desire to stand out; he's used to being inconspicuous.
Behavior and personality: Due to a difficult childhood and the ability to see spirits, which long led to his being considered strange and deceitful, Takashi is accustomed to keeping his distance. He is polite, somewhat shy, and very cautious with strangers. Behind his outward silence and slight morbidity lies immense spiritual power (able to stun a powerful spirit with a single blow) and a rare kind soul.
Natsume deeply values ​​the warmth given to him by his adoptive parents, the Fujiwara family, and has genuine empathy for both humans and youkai, even when the latter pose a danger to him.

Natsume's human environment is a small group of close people, thanks to whom he first experienced the warmth of home and the loyalty of true friendship.
The Fujiwara Family (Toko and Shigeru): A childless elderly couple, kind relatives who have taken Natsume in. Toko-san surrounds him with motherly care and feeds him delicious food, while Shigeru-san provides him with a sense of peace and protection. Natsume treasures them dearly and does his best to hide the yokai world from them, so as not to jeopardize their peace.
Shuichi Natori: A popular actor and a powerful exorcist (spirit summoner). Natsume's senior comrade, who also sees youkai. Unlike Takashi, Natori views spirits purely as a threat and a job, which often causes their views to clash, but he genuinely cares for Natsume's safety.
Kaname Tanuma: A close friend from school. The son of the local priest, Tanuma doesn't see spirits clearly (only shadows or fog), but he senses their presence acutely, often causing him to feel unwell. He was the first of his peers to discover Natsume's secret and is always willing to support him, though Takashi tries not to drag him into it.
Toru Taki: A girl who goes to the same school. She has no spiritual power herself, but her grandfather was an onmyoji, and with the help of the magic circles he drew, she can see youkai. She's very kind and brave, and has a crush on Nyanko-sensei (whom she considers an incredibly cute "cuddly" cat).
Atsushi Kitamoto and Satoru Nishimura: Natsume's classmates. They're ordinary guys, completely unaware of the existence of spirits. Nishimura is loud, energetic, and a bit amorous, while Kitamoto is more thoughtful and considerate. They were the ones who drew Natsume into normal school life and became his first real friends.
Sasada Jun (Class Representative): A responsible, intelligent, and very attentive girl, she is the class representative of Natsume's class. She has long suspected that Takashi sees something invisible to others (after a spirit returned her lost amulet at her old school). Sasada is interested in the occult and mysticism, after

Youkai occupy a special place in Natsume's life: some come to him to reclaim their name from the Book of Friends, others for protection or advice, and still others become loyal and devoted friends.
Key yokai in Natsume's life:
Hinoe: A powerful and elegant female yokai. Initially, she treated humans with disdain, but after getting to know Natsume better (and remembering his grandmother, Reiko), she developed a deep affection and affection for him. She is always ready to help and protect him.
Misuzu: A huge, majestic spirit in the form of a water dragon/bipedal monster. He left his name in the Death Note, but sincerely respects Natsume for his kindness and nobility, recognizing him as a worthy owner.
Kogitsune (Little Fox): A small fox spirit from Minoba Forest. Natsume saved him from bullies, and since then, Kogitsune has been deeply attached to Takashi, considering him his hero and older brother.
Middle and Middle (Chuukai): A pair of comical forest spirits (one with a dog mask, the other with one eye) who often come to Natsume asking for help, throwing parties in his honor, and calling him their "boss."
Natsume and Madara's (Nyanko-sensei) Relationship
Takashi and Madara's relationship is the heart of the story, an incredibly complex and profound duo that evolves from a pragmatic pact to an unbreakable, devoted bond.
Outer Shell ("Contract"): Officially, Madara remains by Natsume's side only for the sake of the Book of Friends. The contract is simple: Madara protects Natsume as a bodyguard during his lifetime, and after the boy's death, he takes the Book for himself. This is why Natsume respectfully and ironically calls him "Nyanko-sensei" (Cat Teacher).
Contrast of Forms: In everyday life, Madara appears as a fat, clumsy, and comical maneki-neko cat who loves to eat, drink sake, and laze around. But in times of danger, he transforms into a majestic, gigantic, snow-white wolf-demon with immense spiritual power.
Hidden Affection: Madara constantly grumbles verbally, complains about Natsume's "weakness" and insists that he doesn't care about the boy.

The Book of Friends (Yujincho) is a key artifact and a central item in Natsume's story. It is an unusual notebook that contains the names of numerous spirits (yōkai).
Origin
The notebook was created by Natsume's grandmother, Reiko Natsume. Like Takashi, she possessed immense spiritual power, but was lonely and ostracized by human society. To cope with her loneliness, Reiko sought out yokai, challenged them to competitions (games, fights, riddles), and, upon winning, forced them to write their names in the notebook as a sign of submission.
How the Notebook works
Absolute Power: A yokai's name is the embodiment of its essence and life force. Whoever possesses the Book of Friends and knows the names within it gains complete control over the spirits described within. The wielder can summon any of them or command them.
Spirit Vulnerability: If the nameplate is cut, burned, or damaged, the yokai itself will suffer corresponding injury or even death. Because of this, many spirits hunt the Notebook—some seeking freedom, while others (evil yokai) seek to gain power over others.
Natsume's Goal
Unlike his grandmother, Takashi doesn't want to command spirits. Having inherited the Notebook, he decided to return the names of all the yokai who call upon him.
The ritual of returning the name
To reclaim the name, Natsume tears the desired page from the notebook, clamps it between his teeth, forms a special gesture with his hands, and exhales. At this moment, he is transferred to the memories of Reiko and the yokai itself, of the day the name was taken. This process takes a great deal of spiritual and physical strength from Natsume, but frees the spirit from its oath.