Taemin's solo contract with his agency,
SM Entertainment, expired in March 2024. He signed a new contract with
BPM Entertainment for his solo promotions. At a fan meeting in July, he revealed that he was planning to release his fifth EP the following month, his first release since switching agencies, and embark on a world tour. On July 29, BPM confirmed that he would release the EP, titled
Eternal, on August 19, coming ten months after his previous EP,
Guilty. It would mark the tenth anniversary of his
solo debut. According to his agency, the title was intended to represent that Taemin would remain the same even in the midst of change. For the first time in his career, Taemin produced the EP himself, participating in every part of the production process, from planning, to songwriting, to music video production. ==Composition==