Elves Come To the World

Twenty-three years ago, space cracks appeared one after another around the world. Behind the space crack is a mysterious special space, which humans call a secret realm.
In the secret realm, a creature called elves appeared. They began to invade the human world through space cracks and fought countless wars with humans.
Until a secret exploration, human beings discovered a mysterious elf research institute, and by deciphering the civilization of another world, they discovered the elf ball, a prop that can conquer elf, so far, a profession called elf hunter began to appear, and quickly The elf alliance was formed to fight against the elf that invaded from the rift in space.
Since then, occupations closely related to elves, such as elves trainers, elves research institutes, and elves cultivators, have been born.