Okatsu

Hyabusa Jao bungled his most recent assignment as an assassin for the Good Men and now he is in trouble with his scary boss, Kazematsuri. As punishment, he has to guard Ryo, the fifteen-year-old son of the opium lord of Okatsu. Jao is prepared to hate his assignment, but unexpectedly he likes the kid a lot, and spends his time training the boy in the rudiments of survival on the street.

Then Ryo is kidnapped.

Tall and elegant Masahiro, Ryo's older brother, is convinced Jao did the deed, and hates him for it. But as Jao pursues the truth and burrows deeper and deeper into the corrupt heart of the opium business, he and Masahiro are slowly drawn into an uneasy collaboration. Together they must uncover the enemy, and team up against a ruthless man who doesn't care who he has to kill to profit.

NOTE: This book was previously published under the title, The Mediocre Assassin's Handbook.