Demon 72

Kuruto Kagemitsu is a boy who has summoned a demon named Shuma, who becomes his unwilling servant. Together, they aim to kill 71 of the 72 demons associated with King Solomon, all of which are allegedly under the control of a single summoner. Shuma is excluded from this list, presumably to avoid his own destruction. Kuruto's motivation is personal—he wants to prove to his mother that he is capable of accomplishing this task.