|Appearances||Siren: Blood Curse|
|Voice Actor||Hattori Seiji|
Seigo Saiga is a doctor and an adopted member of the Saiga family.
At the beginning of the game, he is seen performing the sacrificial ritual, but he ends up helping Howard, Sam, and Melissa. Towards the end of the game, he gives Howard the Uryen and confronts him, apparently so the power of the object can be unlocked and to join his companion, Yukie, in the afterlife. Before time recycles, Seigo commits suicide by putting his gun to his mouth. Afterward, he saves Bella from some Shibito and helps Howard regain consciousness. He then goes to Mount Gojaku and uncovers the Uryen.