The story follows the "strongest juvenile delinquent", Oga Tatsumi, a first year in "Ishiyama High" the school for delinquents. One day while sleeping next to a river he sees a man floating down it, he pulls him to shore and the man splits in half revealing a baby boy. This boy is the son of the demon king and he has been chosen as the one to raise it with the baby's demon maid Hilda. The story follows his life with the child and at the delinquent school.
Beelzebub is a good series to get into, it has some good fighting scenes which are interesting and entertaining.
The characters are good most have there own personalty and catch phrases.
This series shows some potential to get really good but its sorta obvious what will happen next and the main characters is stronger than everyone at this stage, you can get some laugh out of watching this as well and there is really no main plot but the story so far has been good it also has a bit of slice of life but only little, if you like fighting and action you will like this series but if your into a really deep story line with twists and surprises then right this series has not really got to that, but only up to 27 hard to judge the story line. But for me im enjoying it :)