|Fighting Style||Jutsu-Shiki Muteki-Ryū|
|Anime Debut||Trust & Betrayal|
|Voice Actor||John Paul Shephard|
Tatsumi is the leader of the Bakufu's Yaminobu onmitsu and a master of Jutsu-Shiki Muteki-Ryū, a martial art he taught to Inui Banjin. Charged with assassinating the Hitokiri Battōsai, he shows his powerfully strategic side by preparing a three-step attack involving the introduction of a spy to determine the target's abilities & weaknesses, a multi-tiered debilitation attack to dull the target's senses, and using his spy to foster the weakness of sentimentality in the target in case no other weaknesses can be found.
He relies on brains as much as body, formulating the strategy to use Tomoe to create a weakness for Battosai and the set-up of barriers in the 'Binding Forest'. When he fights Battosai, he at first goes in for the kill with his most powerful move, but switches tactics when the weakened Kenshin still proved to be able to strike back at close range. Instead he chips away at his strength with lesser but more malleable attacks. He shows a last gesture of mercy to Kenshin, offering him a choice between a quick and painless death and a prolonged, grueling one. Nearly blinded, deafened and staggering from blood loss, Kenshin lunged at Tatsumi intending to take him down with him, but Tomoe got in the way and was cut down with Tatsumi.
His death is later used as an excuse by Inui Banjin to join the Jinchu campaign.
His name is not revealed directly in the Trust and Betrayal OVA, only being credited with the same name as his manga version in the ending credits. He still remains devious and meticulous as in the manga, but is also portrayed as a deep and thoughtful individual, expanding his loyalty to the Tokugawa Shogunate, by claiming that the nation of Japan itself would decline into a land of unruly chaos and anarchic carnage without its rule, and being driven to kill Kenshin to avenge his underlings as opposed to simply doing so because he was ordered to.