The Longest Nights is adapted from Luly’s illustrated children’s novel ​긴긴밤, published by Munhakdongne in 2021. The book won the Grand Prize at the 21st Munhakdongne Children’s Literature Award and grew into a major bestseller, surpassing 700,000 copies by 2026. The original story follows Norden, the last white rhinoceros, and a young penguin born from an abandoned egg as they endure a succession of long nights while traveling toward the sea.

Library Company premiered the musical adaptation in Seoul on October 15, 2024. The initial run continued through January 12, 2025 and recorded a 75% paid-seat occupancy rate and an audience rating of 9.9. The production returned only two months later for an encore season from March 12 to May 25, 2025, followed by a new Korean season from January 21 to April 5, 2026.

The work also received recognition within the Korean musical industry, including nominations for the Grand Prize and Best Musical in the under-400-seat category at the Korean Musical Awards. In March 2026, the production received additional public attention when South Korean President Lee Jae Myung and First Lady Kim Hye Kyung attended a performance at Link Art Center Dream.

The stage production uses only four actors to create a much larger world. Rather than relying on realistic animal costumes, the performers use simple visual signs: a handheld horn for the rhinoceros, castanets for the penguin, hoses representing elephant trunks, and other multipurpose objects that change meaning throughout the journey. An LED floor expands the small stage into grasslands, desert, night, and sea.