Day and Night arn't made to be right ?

In a world where humanity is separated into two species, one living at night and one living at day, both had evolves with these specials trains of life
When person of the day is still outside at night, he fade out of existence and die, the same happen for the night peoples. For surviving the night, day peoples need to sleep into bath of pure light and night peoples have to sleep into cocoons of darkness.
After quite a while living in peace, day peoples started to calls the night people's monsters because of their look, night peoples, receiving hate for no reason started hating day peoples back.
And it's in this world of tension between the two species that two young men met. One is from the night, the other from the day, condemning them to only be able to see each other when day and night meet.

The cover of the book isn't mine but the other drawings are.
Idk what I'm doing with this.