Max Toonager

Her beloved teacher suddenly vanished from the school. All that remained were a mysterious trunk and a letter, inexplicably entrusted to her. With the determination to "find her teacher," Max boards the traversal train "Solaris" with the trunk in hand. Her first journey takes her to "Tokyo," beyond the border. There, she meets railway security officer Renancuff. This encounter with him triggers her involvement in a battle that will shake the world…

(Source: Kodansha, translated)