High school student Guo Jiawen was accidentally summoned to a different world during his evening self-study and was forced to become a brave man to kill the devil. He fought bloody battles for five years and successfully killed the demon, but was feared by the kingdom and placed under house arrest, and was eventually forced to become the new demon king. After being trapped in another world for twenty years, his only obsession was his mother's song "Treading the Waves". During the decisive battle, the young pastor Vivian sang this hometown song, instantly breaking Guo Jiawen's defenses. When he was on the verge of death, he triggered reverse teleportation and finally returned to his hometown, where he thought about day and night, reunited with his mother who had been waiting for him for twenty years, and fulfilled his promise to take her to see the sea.
