- Ever since Marry was younger, she lived in a small house in the woods with her mother, Shion, who was the daughter of a medusa and a human. "We're Medusae, so if we make eye contact with a human they will be turned to stone". While growing up, she always stuck to their words and hid herself away from the world in the forest. One day, when she was playing outside against her mother's warnings, she was found by humans and almost kidnapped. Although Shion attempted to turn her attackers into stone once she realized what was happening, she as one moment late and both of them were killed with a blunt object. Marry was traumatized by the incident, causing her to fear the outside world.
- When her mother sacrificed herself for her, they were both swallowed up by the Heat Haze. Upon entering it, Azami planted the snake with the "Combining Eyes" ability, which was the core of the Medusa. As a result, on top of the "Eye Contact" ability, that she had already possessed since birth due to her medusa blood, she acquired the medusa's primary ability, the ability to unify all of the "snakes."
- Aware of it or not she is the culprit for changing the present reality into a Heat Haze through meeting the Mekakushi Dan, as well as the "Clearing Eye" snake's schemes.
- After coming back to life she lived in isolation for over a hundred years and by chance, a boy named Seto visited the forest and found her. He had since managed to bring her to the outside world and invited her to join Mekakushi Dan.. After coming to the Mekakushi Dan's hideout, and joining the group, she started a sideline life making fake flowers in her room, which generates a very small income.
- Marry observes Kano and Kido who brought a new member, Momo, to the Mekakushi Dan hideout. Being too shy to introduce herself she needs to get convinced by Kido to come out of her room and to shyly do so. While they talk she decides to make tea, but as she brings it she trips and spills it all over Momo's head. Since she broke her phone she promises to buy her a new one and gets teased by Kano to accept a job to achieve that. Having heard enough of him she uses her ability to freeze him for a short moment, but eventually goes to the mall with everyone as her victim is able to move again, not very happy about the amount of people though.