Nanjiro is the owner of a very powerful tennis corporation and often has rival companies try to ruin him. Echizen is often the target of their ploy which makes it impossible to live a normal life. When he's allowed to go to a public school he meets the regulars who know too well what kind of life that is but that doesn't make him any less of a target to rival companies.
Lucy's childhood was rougher than anyone had ever known. When she ran away it was for the better but when her father uses brutal methods to bring her back, her friends show him what a real family looks like.
When Echizen is gunned down one day during practice he's forced to tell everyone the one thing he hoped he could be hidden from them forever. They soon find themselves in a struggle for survival in a world they never knew they would be involved in but now can't escape until everything is figured out.