"Natsume Yūjin-Chō: Itsuka Yuki no Hi ni" is a 2014 anime film that serves as a continuation of the "Natsume Yūjin-Chō" series. The story centers on Takashi Natsume, a young man who possesses the ability to see yokai, supernatural beings invisible to most humans. This ability stems from his grandmother Reiko, who also had the power to see yokai and bound many of them to her through contracts written in her "Book of Friends." Takashi inherits this book and dedicates himself to returning the names of the yokai to free them from their contracts.

The film’s narrative unfolds during a snowy winter, focusing on a yokai named Yuki, who once formed a bond with a human boy named Shigeru when he was a child. Yuki, a snow-like yokai, is drawn to Shigeru’s kindness and loneliness, and the two develop a fleeting but meaningful friendship. However, as Shigeru grows older, he loses the ability to see Yuki, leaving the yokai heartbroken and longing for their connection. Yuki’s story intertwines with Takashi’s when the yokai seeks his help to reconnect with Shigeru, now an elderly man.

Takashi, accompanied by his loyal yokai companion Nyanko-sensei (Madara), becomes involved in Yuki’s plight. The film explores themes of memory, loss, and the passage of time, as Yuki struggles with the inevitability of change and the fading of bonds between humans and yokai. Takashi’s empathy and determination to help Yuki highlight his growth as a character, as he navigates the complexities of human-yokai relationships and his own connection to his grandmother’s legacy.

The story also delves into Shigeru’s perspective, revealing his lingering memories of Yuki and the impact their friendship had on his life. The emotional core of the film lies in the bittersweet reunion between Yuki and Shigeru, as well as the resolution of their shared past. Through its poignant storytelling, the film reinforces the series’ overarching themes of understanding, compassion, and the transient nature of relationships between humans and yokai.