I can see Ruka trying to pull a school days as she tries to stab Chizuru or Kazuya at a train station in the finale but then Mini shows up, hits this pose and then throws herself and Ruka in front of a train, years later an older and more refined Kazuya will tell this story to his grandchildren while Chizuru smiles on, Kazuya will talk about how sexy Mini was and how she was a good friend.