Imu is Toto's younger sister. When they were young Toto was playing around and crashed inside their mothers room with a tank artifact. However Toto was not scolded for this which made Imu kind of upset. Due to Toto getting away with everything while she tried working so hard, she got very jealous because he was given the Mana Sword by their mother instead of Imu. She did not see why because all he seemed to do was cause trouble. When she trys to wield it herself though she is unable to stabilize the mana and control it properly. Deep down however, they are both still close as brother and sister.