Tatsumasa Saito (斉藤辰政, Saitō Tatsumasa) is an officer of the law from the house of Katsukawa and the husband of Machi.
As Tatsumasa was heading home, his wife Machi was letting him lean on her as he had few drinks. As he found it shameful to lean on her and tried not to, they saw few police officers chasing the criminal who killed lord Horii 2 years ago. As an a police officer himself, Tatsumasa went to chase him too. He eventually caught him and had a conversation with him about his crimes and that he had to avenge his father Tatsuie Saito, who 5 days after Horii's death had to commit oibara. Moments later Machi appeared and recognized the criminal as Manji, in that moment of Manji's hesitation, Tatsumasa attacked, but Manji reacted and killed him.
- Machi... you know I love putting my arm around you. But let's call it quits about here. You may be my wife, but for me to have to lean on a woman... Hell, it's just a samurai thing, you know?
- I've heard a lot about you, pal. They say it was you who cut up the Hatamoto Lord Horii Shigenobu two years ago.
- Your time is up, criminal! Now your soul must be swallowed by the darkness!