Cat Brown enters the ring. Travel journalist Alexandra Berger is set to report on a Japan festival at Duckrath Castle near Düsseldorf. The highlight is a tournament featuring famous Japanese sumo wrestlers who are making a stop there as part of their world tour. However, before the first fighters step into the ring, one of them is found dead in the training room. Diagnosis: heart failure due to excessive obesity. But is there more to it? Thanks to Cat Brown, Alexandra and her colleague Tobias discover that it is a case of murder. In their investigation, they become entangled in a fatal web of rejection, greed, and honor.