Maze

メイズ

The story's heroine. She accidentally saves Princess Mil's life when her house collapses onto Mil's would-be murderer, an event reminiscent of The Wonderful Wizard of Oz, upon falling into the fantasy world. Afterward, she becomes extremely protective of Mil, who often displays intimate feelings or makes sexual advances toward Maze. She is a natural pacifist at the start of the story. She possesses considerable magical ability but is initially much less effective at using it while in her female form. Maze is a fusion of Mei and her brother Akira, who switch places at daybreak and nightfall. During the day, Mei is dominant, while Akira is dominant at night. Maze was brought from the real world as the Eraser to correct an imbalance.
At night, Maze turns into a male with a distinct personality from the daytime female form. He loves to fight, to the horror of the female form, who can be seen trapped in his head shouting at him wherever he tries to fight. In male form, he has vastly increased magical powers. He is very sexually predatory toward almost any pretty girl he meets. Like the female Maze, his memories are mostly wiped or jumbled upon leaving the real world, though they start to recover over time. He is initially portrayed as a sex-crazed, violent monster with little personality, but in time his personality emerges.

Spoiler

The Japanese character for "Akira" can also be read as "Mei" and thus the name "Maze" comes from the term "Meis" as in "two Meis".