Sebastian is one of the twelve characters available to marry in the game. He lives together with his step-father Demetrius and his mother Robin, Maru is his half-sister, but he does not pay her much attention because he thinks his parents pay Maru more love and attention than him. He loves sci-fi novels, videogames, and comics and will often be found in his room for a long time. The actor should be able to portray a grumbling young adult that dislikes how much attention his sister is getting and just generally sound displeased with life.