The twin sister to Junna. Because their parents died in a car crash, She and Junna live together in a house. Senna and Junna support and rely on each other and due to this Senna is very fond of her Onii-chan. However, Senna's existence is doubted as she does not exist in the real world, only in a world which she and Junna had created by their wish, they both wished that Senna will exist, thus, creating a world where she existed. Sadly, a compensation is required to make up for the wish, so their parents had cease to exist in the created world as well as Haruhi, who was her sister, had became Junna's childhood friend instead. She was supposed to be Junna's twin sister in the real world too, but she was not born, which is the reason she did not exist in the original world to make the wish.