Tomco AU

Ok, first off this is my first story of a ship I like and on Wattpad that others will be reading and I'm kinda nervous, scared, and excited all at the same time! Ahem.
Tom was one day looking at a painting that shows his parents, himself on his father's side, and a girl who seems to be his sister on their mother's side. His mother comes knowing he would be there to inform him that they got a letter and three invitations to a Rose Eclipse Gala from his sister Zelia. Disappointedly his parents couldn't go since the gala would last all night so she suggests inviting Star and her friends. But this gala is not an ordinary gala, and when Star brings her best friends and Marco to the gala who would've expected that a demon would be soulmates with a human?