Thirty-five-year-old novelist Makio Koudai never had a good relationship with her older sister Minori, who always berated her for being different. Due to this, Makio is not stricken with grief upon hearing the news that Minori and her husband died in a car crash. But when Makio is asked to identify their bodies, she runs into her 15-year-old niece, Asa Takumi, whom she has not seen in years. As Asa struggles to process her parents' death, Makio reassures her that her complicated feelings are valid and suggests that the teenager start writing in a diary as a way to cope with the loss. Upon learning that no other relatives wanted to take in Asa, Makio decides to become her guardian despite her lack of experience. In a world full of uncertainty, the novelist and teenager must learn to live with each other while figuring themselves out.

The Yuzuki family, which consists of four brothers, lost their parents two years ago. Hayato, the eldest son, is a hard worker and the pillar of the family. Mikoto, the second son, is calm and collected, but he has a soft spot for his younger brother Minato, whom he adores and thinks is cute. Minato, the third son, is energetic and adores his brothers, but he is clumsy and awkward. Gakuto, the fourth son, is a studious and mature first-grader who is often referred to as a wise man. The manga depicts the four brothers' daily lives as they navigate their family, school, and community. (Source: MAL News)

As a young child, Takashi Natsume believed his ability to see youkai to be nothing but a curse. Now a high school student, Natsume has managed to heal from his old wounds and form unbreakable bonds with humans and youkai alike. Natsume's newfound friendships—including the one with his spirit bodyguard Madara, nicknamed Nyanko-sensei—are often interlaced with his duty to return the names of the spirits written inside the Book of Friends, his late grandmother Reiko's keepsake. While more remarkable youkai reach out to him, Natsume discovers that he still has much to learn about the world that surrounds him.

Takashi Natsume has grown accustomed to his encounters with youkai through the Book of Friends, which contains the names of youkai whom his grandmother, Reiko Natsume, has sealed in contracts. These encounters allow Natsume to better understand the youkai, Reiko, and himself. The Book of Friends is a powerful tool that can be used to control youkai; it is sought after by both youkai and exorcists alike. Natsume just wants to live out his daily life in peace but is constantly disrupted by these experiences. If he is to end this torment, Natsume must explore more about the book and the world of exorcism, as well as begin to open his heart to those who can help him.