In the year 2500, biochemical gases from a secret experimental base unfortunately escaped. From then on, people grew animal ears and developed supernatural powers.
The government failed to eradicate the abnormality, but was overthrown by the abnormality.
From then on, there were only two kinds of people in the world, superpowers and non-superpowers.
Our story is the story of 400 years after supernatural beings ruled the world, which is the year 2900.
The singing cicada is not a real cicada, but a plan, one that may change the world...