Background
Saya is girl popular among other students due to her figure and overall attractiveness, though she is a renowned airhead. at night, she can be found at the school wandering around in order to protect a "treasure" from those she calls the "darkness executives" and even has to fight them for it.
Saya's true identity is Aya, a normal girl with a father as a doctor who volunteered in various countries that are not well-off. Since they had to move frequently, she did not have enough time for any deep relationships with others or school. During her childhood, she briefly befriended Riki during her brief stay in Japan, playing soccer with each other. One day, when Saya and her father were about to return to Japan and end their traveling, Aya became involved in an accident due to a flood. She was on the verge of death when she, by chance, noticed the artificial world Kyousuke has created and decided to enter it. Inside, she materialized as Saya Tokido, a character from Kyousuke's favorite manga, which incidentally happened to be her favorite as well, given to her by a Japanese tourist. Due to this, Kyousuke originally thought she was created due to his hidden desire, and intended to leave her alone, but after seeing her interacting with Riki, he realizes that she is actually an "interloper" to his world and tries to make her leave, since her existence causes Riki to stray away from the others because he had been threatened by the "darkness executives" with Rin's life. This is implied during the "replay" portion of her route where all the traps that used to be merely a prank in the labyrinth and shooting mini-game actually turn lethal, and significant changes to the maze are made to hinder Saya. Also, the head of the "darkness executives" (who is actually Kyousuke) tells Saya at the beginning (and each subsequent replay) that she will be better off if she shot herself in the head.
