10 years ago, the children have lost their family members because of demon attack.
Elf Emilia and Human Roy are the two people who came spent together from an early age
to live helping each other as brother and sister choose to go with a force against the devil.
One of their request is “Maikomu”
“I want to kill the devil that laying in the temple,”
two people towards the suspicious temple but There is only one Demon there..a Succubus.