- "They knew they were wrong."
- —Shimasani, talking about ancestors
Shimasani was born on May 28, 1919, a year after the end of World War I.
At some point of her life, Shimasani married her future husband, and nine months later, she gave birth their first and only son, Paul, born on June 30, 1958, at some point, her husband died.
She is an elderly woman, who lives with her son and grandsons on a remote ranch in Navajo.
Shimasani is a descendant of the Dineh people attacked by U.S. military forces. Her ancestors resorted to summoning a terrible entity, Yé'iitsoh, to gain vengeance and defend themselves. Yé'iitsoh was not satisfied with just killing the soldiers, and turned on its summoners.
When Jodie presents Shimasani with four of the five talismans worn by the summoners, Shimasani stirs and reveals that she recalls the incantation used for the original ceremony as it was passed down through her ancestors to her. Jodie uses Aiden to view the original ceremony and together, they work to return Yé'iitsoh to the Infraworld.
Regardless of the outcome of the ritual, Shimasani dies, and is buried in the sacred grounds of the Navajo. Her son, Paul, will be buried alongside her if he is not saved by Jodie.
- Shimasani was born a year after the end of World War I.
- Shimasani will appear with Paul, Cory and Jay watching as Jodie leaves Navajo at the end of the chapter, even though she has already died.
- The same happens to Paul when he's dead. These could be the spirits of the two bidding Jodie goodbye.
- Shimasani will die, regardless of how well the ritual is performed. There is no given explanation to her death. However, it can be assumed that, considering she is already very elderly, the effort of performing the ritual may have exhausted her to the point of death. She may have also been attacked by one of the entities.
- In one of the flashbacks Jodie sees, a baby is shown wrapped in the same colourful blanket that the elderly Shimasani wears over her lap. This blanket was passed down from mother to daughter until it was given to Shimasani.
- The Navajo name "Shimasani" means "Grandmother".
- Shimasani shares some similarities with Agatha, a supporting character from another Quantic Dreams game titled Fahrenheit: Indigo Prophecy (2005), as both:
- are elderly and wheelchair bound.
- will die no matter what the player does.
- aid the main character in defeating an antagonist through giving them a vision (Agatha aids Lucas into uncovering who made him murder a man by helping him recover his memory and identify the real killer and main antagonist, the Oracle, while Shimansani aids Jodie in finding out how to defeat Yé'iitsoh by showing her a flashback of how the ritual used to summon the entity was done in order to show how to perform the ritual to send Yé'iitsoh back).