It's about a girl running to school late. She gets killed by a bus while running into a cat and ends up at school in Hell.
This is "Hells", also known as "Hell's Angels".
Amagane Rinne, an up-beat schoolgirl, has died. Even though she is dead, she still has to go to school. But if she's dead, where would she go to school? In Hell, of course! But making friends in a school filled with demons isn't as easy as it sounds.... and doesn't sound like much fun!