"The Tunnel to Summer, the Exit of Goodbye" centers around a mysterious urban legend involving a tunnel that grants wishes but exacts a heavy toll. The protagonist, Kaoru Tono, is a high school student grappling with the loss of his younger sister, whose death has left his family fractured. One day, Kaoru stumbles upon the enigmatic tunnel, known as the "Urashima Tunnel," which is said to distort time and space. Those who enter can make a wish, but for every wish granted, an equivalent amount of time is taken from their life. Kaoru’s initial skepticism gives way to curiosity as he begins to explore the tunnel’s properties. He is joined by Anzu Hanaki, a classmate with her own reasons for seeking the tunnel’s power. Anzu is determined to use the tunnel to change a painful event from her past, and her presence adds emotional depth to the narrative as the two form a bond over their shared struggles. Together, they navigate the tunnel’s surreal and often perilous environment, confronting their fears and regrets while uncovering the true nature of the tunnel’s power. As Kaoru and Anzu delve deeper into the tunnel’s mysteries, they encounter other individuals who have been drawn to its allure, each with their own motivations and tragic backstories. The tunnel’s rules become increasingly complex, forcing the characters to weigh their desires against the irreversible consequences of their actions. Themes of loss, grief, and the passage of time are woven throughout the story, as Kaoru and Anzu grapple with the ethical and emotional dilemmas posed by the tunnel. The narrative builds toward a climactic decision as Kaoru and Anzu must choose whether to use the tunnel’s power to alter their lives or accept their pasts and move forward. The story’s resolution hinges on their ability to confront their pain and find meaning in their experiences, even as the tunnel’s enigmatic nature leaves lingering questions about fate and free will. The series balances its fantastical elements with grounded character development, creating a poignant exploration of human resilience and the cost of second chances.