This is a Jung Joon-woo x OC. Jung Joon-woo is the real boss behind Babel, and better known as Jung Han-seok. His little brother, Jung Han-seo, is who everyone thinks is the boss. In this fanfiction, the OC, Aria Cassano, is Vincenzo's only biological little sister that was supposed to be in Italy marrying one of the Cassano Family's ally family, the Alfanos. When she shows up, not even telling Vincenzo, she sees that he has met more people and is a lot more social with his life. Even though she is his younger sister, Aria is not known to the world, and the Babel's real Chairman does not know anything about her. But when he lays his eyes on her, he seemed to be falling in love.