Book 2

Blade of the Samurai

by Susan Spann

Published 15 July 2014
Master ninja Hiro Hattori is trying to sleep when he has an unexpected visit from his friend Kazu, a fellow shinobi and member of the same ninja clan working undercover at the shogunate. Kazu says that Saburo, the Shogun's cousin, has been stabbed to death within the walls of the Shogun's palace with Kazu's dagger, and that though he is innocent, he fears he will be blamed for the murder. He begs Hiro's help in escaping the city. But before he can flee, Hiro and Father Mateo, the Jesuit priest under Hiro's protection, are summoned to the palace to aid in the investigation. There they learn of a plot to assassinate the Shogun and overthrow the ruling Ashikaga clan. With Lord Oda, a rival warlord, scheduled to arrive in Kyoto soon and the murderer poised to strike again, Hiro must use his assassin's skills to reveal the killer's identity and protect the Shogun. Kazu, trapped in the city, still will not admit where he was at the time of the murder, and this makes Hiro doubt his innocence. Other suspects include the maid who found the body, Saburo's wife, and the stable master.
Unfortunately, the Shogun demands the murder solved before Lord Oda arrives, and if the murderer can't be brought to justice, Hiro and Father Mateo may have to die in his place.

Book 4

The Ninja's Daughter

by Susan Spann

Published 2 August 2016
Autumn, 1565: When an actor's daughter is murdered on the banks of Kyoto's Kamo River, master ninja Hiro Hattori and Portuguese Jesuit Father Mateo are the victim's only hope for justice. As political tensions rise in the wake of the shogun's recent death, and rival warlords threaten war, the Kyoto police forbid an investigation of the killing, to keep the peace-but Hiro has a personal connection to the girl, and must avenge her. The secret investigation leads Hiro and Father Mateo deep into the exclusive world of Kyoto's theater guilds, where they quickly learn that nothing, and no one, is as it seems. With only a mysterious golden coin to guide them, the investigators uncover a forbidden love affair, a missing mask, and a dangerous link to corruption within the Kyoto police department that leaves Hiro and Father Mateo running for their lives.

Book 5

Betrayal at Iga

by Susan Spann

Published 11 July 2017
Autumn, 1565: After fleeing Kyoto, master ninja Hiro Hattori and Portuguese Jesuit Father Mateo take refuge with Hiro's ninja clan in the mountains of Iga province. But when an ambassador from the rival Koga clan is murdered during peace negotiations, Hiro and Father Mateo must find the killer in time to prevent a war between the ninja clans. With every suspect a trained assassin, and the evidence incriminating not only Hiro's commander, the infamous ninja Hattori Hanzo, but also Hiro's mother and his former lover, the detectives must struggle to find the truth in a village where deceit is a cultivated art. As tensions rise, the killer strikes again, and Hiro finds himself forced to choose between his family and his honor.

Book 6

Trial on Mount Koya

by Susan Spann

Published 3 July 2018
Master ninja Hiro Hattori and Jesuit Father Mateo head up to Mount Koya, only to find themselves embroiled in yet another mystery, this time in a Shingon Buddhist temple atop one of Japan's most sacred peaks. November, 1565: Master ninja Hiro Hattori and Portuguese Jesuit Father Mateo travel to a Buddhist temple at the summit of Mount Koya, carrying a secret message for an Iga spy posing as a priest on the sacred mountain. When a snowstorm strikes the peak, a killer begins murdering the temple's priests and posing them as Buddhist judges of the afterlife-the Kings of Hell. Hiro and Father Mateo must unravel the mystery before the remaining priests-including Father Mateo-become unwilling members of the killer's grisly council of the dead.

Book 7

Ghost of the Bamboo Road

by Susan Spann

Published 12 November 2019

Book 8

Fires of Edo

by Susan Spann

Published 15 February 2022

Claws of the Cat

by Susan Spann

Published 16 July 2013
When a samurai is brutally murdered in a Kyoto teahouse, master ninja Hiro has no desire to get involved. But the beautiful entertainer accused of the crime enlists the help of Father Mateo, the Portuguese Jesuit priest who Hiro is sworn to protect, leaving the master shinobi with just three days to find the killer and save the girl and the priest from the dead man's vengeful son. The investigation plunges Hiro and Father Mateo into the dangerous waters of Kyoto's floating world, where they quickly learn that everyone from the elusive teahouse owner to the dead man's dishonored brother has a motive to keep the samurai's death a mystery. A rare murder weapon favored by ninja assassins, a female samurai warrior, and a hidden affair leave Hiro with too many suspects and far too little time. Hiro must use his ninja skills in a secret mission designed to reveal the assassin's identity and save the Jesuit from execution. But the mission uncovers a host of secrets that threaten not only Father Mateo and the teahouse, but the very future of Japan.

Flask of the Drunken Master

by Susan Spann

Published 14 July 2015
"August 1565: When a rival artisan turns up dead outside Ginjiro's brewery, and all the evidence implicates the brewer, master ninja Hiro Hattori and Portuguese Jesuit Father Mateo must find the killer before the magistrate executes Ginjiro and seizes the brewery, leaving his wife and daughter destitute. A missing merchant, a vicious debt collector, and a female moneylender join Ginjiro and the victim's spendthrift son on the suspect list. But with Kyoto on alert in the wake of the shogun's recent death, a rival shinobi on the prowl, and samurai threatening Hiro and Father Mateo at every turn, Ginjiro's life is not the only one in danger. Will Hiro and Father Mateo unravel the clues in time to save Ginjiro's life, or will the shadows gathering over Kyoto consume the detectives as well as the brewer? Flask of the Drunken Master is the latest entry in Susan Spann's thrilling 16th century Japanese mystery series, featuring ninja detective Hiro Hattori and Jesuit Father Mateo"--