The story revolves around two boys Asta and Yuno. The world is full of magic and the boys want to become the Wizard King (highest rank of magic knights) but Asta does not have any magic whereas Yuno is a genius. The story starts a bit slow but it is one of the best mangas I've ever read. Definitely a good shonen manga. The idea of magic is interwoven with the characters in a very successful way.