Book Four: Duet
Childhood friends with opposing personalities, Mingi and Ryan, dream of becoming rock stars but find themselves on the Infinity Train. They explore the locomotive's inner puzzles — and their own relationship — in order to return home, together.
202110 EpisodesAnimation, Sci-Fi & Fantasy, Action & Adventure
Episode Guide
Once great friends, Ryan and Min-Gi's relationship slowly dissolves over the course of years of disgruntlement, culminating with their reunion in the restaurant.