The Shinobi: Toro is automatically found once you complete Set Up the Ambush. He will appear in the Monk's district of Koyasan in Kii once that quest is completed and you have turned off all the lamps ...

At the mansion, hop onto the roof of the building where she is sitting. She is being guarded by three Shinobi. You can take all of these out with Kunai, using the roof to regain stealth when they lose ...