"Zō Ressha ga Yatte Kita" is a short anime series that revolves around the arrival of a mysterious train, the titular "Zō Ressha" or "Elephant Train," which appears in a small, rural town. The train is not an ordinary one; it is operated by anthropomorphic animals, primarily elephants, who serve as its crew. The train's purpose is to collect and transport items that hold significant emotional value to the townspeople, often items that are no longer needed but carry deep sentimental weight.

The narrative unfolds through episodic encounters between the train's crew and the townsfolk. Each episode focuses on a different character who must decide whether to part with a cherished possession. The items range from childhood toys to family heirlooms, each tied to memories and emotions. The crew of the Zō Ressha, led by the calm and wise elephant conductor, assists the characters in confronting their feelings and making peace with their past. The process is not merely about letting go but also about understanding the importance of memories and how they shape one's identity.

The main characters include the conductor, who serves as a guiding figure, and other animal crew members who provide support and insight. The townspeople, though secondary characters, are central to each episode's emotional core, as their personal stories drive the narrative. The series explores themes of loss, memory, and the passage of time, often with a gentle, melancholic tone. The interactions between the train's crew and the townsfolk are marked by a sense of respect and empathy, emphasizing the value of human connections and the significance of personal history.

The setting is a quiet, almost timeless rural town, which enhances the surreal and reflective atmosphere of the series. The arrival of the Zō Ressha is both a literal and metaphorical event, symbolizing the inevitability of change and the need to move forward while honoring the past. The series balances its fantastical elements with grounded, relatable emotions, making it accessible to a wide audience. Through its episodic structure, "Zō Ressha ga Yatte Kita" offers a contemplative exploration of how people navigate the complexities of memory and letting go.