Yamamoto headed the Munich branch of Kadofuku company. Following Hans Georg Schuwald's resumption of financial activities, corporations across Germany were eager to establish good relations with him. When Schuwald’s secretary, Johan, requested Yamamoto to locate a copy of "The Nameless Monster," he promptly traveled to the Czech Republic to find one.
Before the incident, Yamamoto was also a friend of Tenma and had arranged to meet Heinrich Lunge to answer some questions. Due to his sudden trip, Yamamoto postponed meeting the inspector until later that evening at a bar. There, Lunge noticed Yamamoto’s copy of "The Nameless Monster" and began investigating it, eventually leading him to travel to Prague to uncover more about the enigmatic Emil Sebe (Franz Bonaparta).
(Source: Monster Wikia)
