No premiere date announced yet. The new PV is here. Check out the Crunchyroll article for more information. Synopsis for the first season from AniList:
Suzuki Iruma has just been abandoned and sold to a demon by his irresponsible parents! Surprisingly, the next thing he knows he’s living with the demon who has adopted him as his new grandson, and has been transferred into a school in the demon world where his new “demon” grandfather works as the principal. Thus begins the cowardly Iruma-kun’s extraordinary school life among the otherworldly as he faces his true self, takes on challenges, and rises to become someone great…
That’s because this started as a manga not a light novel. Different mediums use different ways to grab viewers attention and most light novels summarize the entire plot in the title. I highly recommend reading the manga for this series, it’s very good (can’t say if the anime is any good, but they must be doing something right if it’s entering the fourth season).