Tale of the Nine Tailed 1938

Thanks to Rang's sacrifice, Yeon became a person and had a happy ending with Ji-a. However, he visits the Afterlife Immigration Office after learning that his sinful brother Rang cannot be reborn. There, Yeon makes an unjust contract to serve again for Rang's reincarnation. Due to this, Yeon gets back as a nine-tailed fox and even crash-lands in 1938. While carrying out his mission, he encounters young Rang, who is alive again but as an enemy, just as their relationship back then.