After All Not

This is a world where humans and alien races coexist. Hundreds of years ago, humans and alien races were in a hostile relationship. Both sides wanted to eradicate the other, but in the end both sides suffered losses. Therefore, humans and alien races signed a contract, and the two sides coexisted peacefully in the future. As time goes by, in the 21st century, alien races gradually disappear from human sight, but alien races are still living with humans. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.