S1·E14 Shame! Kabuto Family's Grave Sin Exposed!

With Shiro and Tsubasa together in one place, Schtroheim begins to reveal details of the Kabuto family's twisted past - that he and Tsubasa were once engaged, that she eloped with Kouji and Shiro's father Kenzo Kabuto and that before the end of the expedition, she killed Kenzo with her own hands. Their conversation is cut short by the arrival of Baron Ashura, who demands to take Schtroheim's creation - the giant robot Donau α1. Ashura reveals that Schtroheim had agreed to complete the machine for Dr. Hell, as repayment for bringing him back to life after an accident that killed him. However, Schtroheim insists that the machine is not complete and chases Ashura and his forces out of his house. With Ashura gone, Schtroheim and Tsubasa have a cryptic conversation about Mycanae and the Kabuto family but are interrupted by the arrival of the once thought dead Kenzo Kabuto.