As a result of the devastating war between the demonic force and human legion,
the demon lord was defeated by the hero. As the demonic army was dismantled,
demonic beings now have no way to live but symbiotically with humans.
Phio, once a servant for the demon lord, is now also living in a human society
with some night entertainment job, pretending to a human girl.
One night, she is stickily pushed by a customer in an off-street alley.
"I know it are a demon! I may report it to authority ... It depends on my feeling."
In this severe situation, saving her from that vicious guy is the "demon lord",
who was truly defeated and dead in the past war!