The PCs ran into Bayushi Sozui masquerading as a member of the Tonbo family. She was the mastermind of the Scorpion infiltration of Kenson Gakka, which included the murder and impersonation of Akodo Ikare, the commanding officer of the garrison (the actual culprit of which crime is still at large). Sozui disappeared during the fighting, and is rumored to have been seen in Toshi Ranbo wo Shien Shiite Reigsaho in the recent past.
Update: Legacy of the Forge
The PCs successfully eliminated Bayushi Sozui as she attempted to disrupt the ritual to banish the spirits of Toshigoku from Ningen-do. At her death, she was revealed to have no less than five of the brands they previously encountered on the Scorpion assassins at Shiro Iuchi.